Source: NORTH CAROLINA STATE UNIV submitted to NRP
FLAVOR AND FLAVOR CHEMISTRY OF DAIRY PRODUCTS.
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1001754
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Nov 7, 2013
Project End Date
Sep 30, 2018
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695
Performing Department
Food, Bioprocessing, and Nutrition Sciences
Non Technical Summary
The research program of the PI is focused on the flavor and flavor chemistry of dairy products including research with descriptive sensory analysis and consumer testing. PI Drake has conducted several studies focused on flavor and texture and flavor chemistry of cheese and dried dairy ingredients. We solve problems of flavor and texture for dairy products. Our research applies directly to the increased quality of dairy products consumed everyday.
Animal Health Component
90%
Research Effort Categories
Basic
10%
Applied
90%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5033450309033%
5033430309034%
5033470309033%
Knowledge Area
503 - Quality Maintenance in Storing and Marketing Food Products;

Subject Of Investigation
3430 - Cheese; 3450 - Milk; 3470 - Other dairy cattle products;

Field Of Science
3090 - Sensory science (human senses);
Goals / Objectives
Objective 1:To identify and quantify chemical flavor components responsible for specific flavor attributes in dried dairy ingredients Objective 2:To characterize and quantify chemical flavor components due to specific unit operations in dried dairy ingredients or cheeses Objective 3: To characterize consumer perception of selected products and relate perception to quantifiable sensory or chemical measurements.
Project Methods
Objective 1 1. The dried ingredient flavor language developed by PI Drake (Drake et al., 2003; Russell et al., 2006) is used to document flavor profiles of samples. A specific goal will be to determine the impact of various unit operations and storage on dried milk and whey ingredient flavors. Products are manufactured by industry collaborators or processed in the NCSU Creamery pilot plant. 2. Flavor volatiles will be extracted from selected products by direct solvent extraction with high vacuum distillation and SPME. Preliminary work in our laboratory on this objective has been initiated and successful trapping of volatile flavor components is achieved in this manner. Chemical compounds identified as potential chemical anchors will be evaluated qualitatively and quantitatively in model matrices. Compound(s) will be added to each matrix at the concentration(s) encountered in the dried ingredient exhibiting the flavor attribute. A trained sensory panel will evaluate the spiked models in blind studies (eg. the panel will not know what descriptor is being studied). Blind studies will ensure that a true indication of the sensory impact of the compound is addressed. When a compound or compounds have been identified by the sensory panel as associated with a particular flavor, threshold studies and the linear dose response behavior of the compound(s) in the milk matrix will be determined. GC-O and AEDA as well as previous literature from milk flavor analysis allow us to identify qualitative aspects and relative intensities of isolated aroma components, but do not indicate the sensory impact of chemical components in a milk matrix or the concentration range within which these components exhibit a significant impact. Identification of the linear dose response behavior of chemical components will enable clarification of the role a particular chemical component plays in milk flavor perception across a concentration range and will also result in identification of protocols for preparation of reference samples for panel training. Threshold studies of identified chemical reference components confirmed by descriptive analysis will be conducted by ascending forced choice trials (Meilgaard et al., 1991; Lawless and Heymann, 1998) using screened experienced panelists (n=25). Panelists will be screened for anosmia and the ability to differentiate and scale basic taste solutions. Objective 2 1. Screening and identification of ingredients: Dried ingredients containing elevated levels of specific flavor attributes for which chemical anchors have not been identified will be selected from commercial sources or manufactured in the NCSU pilot plant. These will be later subjected to exhaustive flavor composition analyses (explained below the established sensory testing protocols and procedures, including sensory terms and rating scales, will be used (Meilgaard et al., 1999; Drake et al., 2003). 2. Flavor analysis and characterization--identification/quantitation of key odorants: For each ingredient (pair or group) two methods for isolation of volatile compounds dynamic headspace-thermal desorption, and solvent extraction-high vacuum distillation will be applied. These are complementary methods that will allow us to sample the wide range of aroma compounds in the cheese--from highly volatile components to intermediate and semi-volatile components (Horwood, 1989; Zehentbauher and Reineccius, 2000). We will use standard addition methodology using 2-methyl-3-heptanone as internal standard. Solvent extraction (ether)-high vacuum distillation has been previous described (Milo and Reineccius, 1997; Suriyaphan et al., 2000). Separation and analysis of flavor components will be conducted by GC-MS on two different stationary phases (nonpolar DB5 and polar FFAP columns). GC-olfactometry (sniffing of GC effluent), including both GCO of decreasing headspace samples (GCO-H and GCO-DHS) and aroma extract dilution analysis (AEDA), will be used to indicate and compare (between ingredients) potent odor-active compounds (Milo and Reineccius, 1997; Cadwallader and Baek, 1998; Cadwallader and Howard, 1998; Suriyaphan et al., 1999; Chen et al., 2000; Zehentbauer and Reineccius, 2000). Evaluation of existing literature will also be conducted to aid in identification/clarification of potential chemical anchor compounds. Objective 3 Traditional and non-traditional preference mapping techniques will be applied or developed to relate consumer perception to quantifiable sensory or instrumental analyses on selected dairy foods (cheese, cottage cheese, sour cream, fluid milks). Category surveys will be conducted on each product. The purpose of a category survey is to define the sensory space (sensory properties and sensory variability) of a particular food type (Lawless and Heymann, 1999). To conduct the category survey, a descriptive sensory panel will be trained to identify and quantify sensory properties (appearance, flavor, texture) of each product. All sensory testing will be conducted in compliance with NCSU Institutional Review Board for Human Subjects. Panelists will be selected based on time available, interest, and basic taste acuity. Panelists will subsequently be trained to identify and quantify sensory attributes of the beverages using the Spectrum technique (Meilgaard et al., 1999; Drake and Civille, 2003). Briefly, panelists will be presented with an array of commercial products to evaluate and discuss. These sessions will consist of language identification. Consistent with SpectrumTM descriptive analysis training, panelists will be presented with reference solutions of sweet, sour, salty, and bitter tastes to learn to consistently use the universal intensity scale (Meilgaard et al., 1999; Drake and Civille, 2003). Following language identification and scale usage, panelists will discuss products and the identified attributes for several training sessions. Analysis of data collected from training sessions will be used to confirm that the panel is operating in unison as an instrument and is ready for formal product analysis (Meilgaard et al., 1999). Consumer acceptance testing will be conducted on representative products within each category. As with descriptive analysis, testing on each product category will be conducted separately. For each product type, 6 to 10 representative products will be selected for consumer testing. The protocol will consist of a questionnaire regarding demographics, food consumption, choice, and attitudes followed by evaluation of products. Testing will be conducted on multiple days such that each consumer evaluates all products. Consumers will evaluate each product for flavor, texture, and overall acceptance on a nine-point hedonic scale (Lawless and Heymann, 1998; Meilgaard et al., 1999). Additionally, acceptance and intensity perception of other attributes will also be scaled. These attributes will be identified from descriptive analysis results and our previous work with permeate. A minimum of 100 consumers will be recruited. Consumers will receive food treats and gift certificates for participation. Traditional preference mapping techniques will be applied to identify key drivers. Additionally other techniques to characterize consumer perception will also be evaluated including focus groups, qualitative multivariate analysis and non-traditional preference mapping.

Progress 11/07/13 to 09/30/18

Outputs
Target Audience:The target audience is the food industry. Foods and ingredients are used in a variety of applications. Consistent sensory quality is required to optimize existing markets and expand into new ones. Flavor problems cost the food industry billions of dollars annually. The goal of my research program is to provide quantifiable and applicable ways to document and compare sensory perception of flavor and to further define the role that specific volatile compounds have on sensory quality. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project has provided numerous training and professional development opportunities. More than 40 peer reviewed papers have been published and more than 60 oral or poster presentations have been given by graduate students at professional meetings in the past 5 y. Fourteen graduate students have received thesis degrees. How have the results been disseminated to communities of interest?The project results have been widely disseminated. More than 40 peer reviewed papers have been published, more than 60 oral or poster presentations have been given by graduate students at professional meetings, and more than 30 oral presentations or workshop trainings have been provided by the PI. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objectives 1 and 2: The roles of specific unit operations on the sensory quality of dried dairy ingredients weredocumented and specific recommendations were made to optimize the quality of these products. These outcomes are documented in the publication record and published reviews within the timeframe of this project. Objective 3: The specific drivers of consumer liking and disliking were established for sour cream and for Gouda cheese, bacon and tomatoes.Key attributes that consumers desire for protein products were established.These outcomes are documented in the publication record and published reviews within the timeframe of this project.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Yuanzhu, L., Joyner, H., Lee, A.P. and Drake, M.A. 2018. Impact of pasteurization and fat on milk: relationships among rheological, tribological and astringency behaviors. Int. Dairy J. 78:28-35.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Li, Y., Joyner (Melito), H., Carter, B.G. and Drake, M.A. 2018. Effects of fat content, pasteurization method, homogenization pressure, and storage time on the mechanical and sensory properties of bovine milk. J. Dairy Sci. 101: 2941-2955.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Carter, B.G. and Drake, M.A. 2018. The effects of processing parameters on whey protein ingredients. J. Dairy Sci. 101:6691-6702.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Parker, M.E., Lopetcharat, K., and Drake, M.A. 2018. Consumer acceptance of natural sweeteners in protein beverages. J. Dairy Sci. 101: 8619-8640.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Wagoner, T., McCain, H.E., Foegeding, E.A. and Drake, M.A. 2018. Food texture and sweetener type modify sweetness perception in whey protein-based model foods. J. Sensory Stud. 33:1-9.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Carter, B.G., Patel, H., Barbano, D.M., and Drake, M.A. 2018. The effect of spray drying on the difference in flavor and functional properties of liquid and dried whey proteins, milk proteins and micellar casein concentrates. J. Dairy Sci. 101:3900-3909
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Stout, M.A., Benoist, M., and Drake, M.A. 2018. Simultaneous carotenoid and vitamin analysis of milk from total mixed ration fed cows optimized for xanthophyll detection. J. Dairy Sci. 101:4906-4913.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Jo, Y., Benoist, D.M., Ameerally, A., and Drake, M.A. 2018. Sensory and chemical properties of Gouda cheese. J. Dairy Sci. 101: 1967-1989.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: McCain, H.R., Kaliappan, S. and Drake, M.A. 2018. Sugar reduction in dairy products. J. Dairy Sci. 101:8619-8640.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Jo, Y., Benoist, D.M., Barbano, D.M., and Drake, M.A. 2018. Flavor and flavor chemistry differences among milks processed by high temperature short time pasteurization or ultrapasteurization. J. Dairy Sci. 101:3812-3828.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Harwood, W.S. and Drake, M.A. 2018. Identification and characterization of fluid milk consumer groups. J. Dairy Sci. 101:8860-8874.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Cheng, N., Barbano, D.M., and Drake, M.A. 2018. Hunter vs CIE color measurement systems for analysis of milk based beverages. J. Dairy Sci. 101: 4891-4905.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience:The target audience is the food industry. Foods and ingredients are used in a variety of applications. Consistent sensory quality is required to optimize existing markets and to expand into new market segments. Flaovr problems cause the food industry billions of dollars annually. Consistent quantifiable ways to document and compare flavor along with an understanding of the relationship(s) between chemical components, consumer perception and unit operations in processing are needed. The goal of my research program is to provide quantifiable and applicable ways to document and compare sensory perception of flavor and the further define the role that specific chemical compounds of food have on sensory perception of flavor. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Results have been disseminated to the food industry and other relevant stakeholders through presentations at professional meetings, invited on-site presentations and peer reviewed publications. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objectives 1 and 2.Fluid milk is traditionally pasteurized by high temperature short time (HTST) pasteurization (72°C for 15s). Ultra-pasteurization (UP) extends milk shelf life (at least 138°C for 2s). The UP process can be done by indirect heating (IND) or by direct steam injection (DSI). The influence of these two UP methods on milk flavor has not been widely investigated. The objective of this study was to compare the effect of HTST, IND-UP, and DSI-UP on sensory perception of fluid milk. Raw skim and standardized 2% milks were pasteurized at 140°C for 2.3s by IND or DSI or by HTST (78°C, 15s) and homogenized at 20.7 MPa. The processed milks were stored in light shielded opaque HDPE containers at 4°C and examined by descriptive analysis and microbial analysis on days 3, 7, and 14. Furosine and serum protein (SP) denaturation analyses were performed on day 0 and day 14 as an indicator of heat treatment. Lastly, consumer acceptance testing was conducted at day 10 with adults (n=250) and children (ages 8 to13 y, n=100) who were self-reported consumers of skim or 2% milk; consumers only received samples for either skim or 2% milk. Milks treated by HTST had lower cooked flavor than either UP milk. Milks heated by DSI-UP were characterized by sulfur/eggy and cooked flavors while IND-UP milks had higher sweet aromatic and sweet taste compared to DSI-UP milk. Aromatic flavor intensities of all milks decreased across 14 d storage. Furosine concentrations and SP denaturation were highest for the IND treatments, followed by DSI, and lastly HTST. Furosine content in both skim and 2% milk increased with time but the increase was faster in IND-UP skim milk. Adult and child consumers preferred HTST milk over either UP milk, regardless of fat content. Ultra-pasteurization by IND or DSI did not impact consumer acceptance 10 days post processing, but traditional HTST milks were preferred by consumers of all ages. Fluid milk consumption in the United States has continued to decline. As a result, the level of dietary vitamin D provided by fluid milk in the U.S. diet has also declined. Undesirable flavor(s)/off-flavor(s) in fluid milk can negatively impact milk consumption and consumer product acceptability. The objectives of this study were to identify aroma active compounds in vitamin concentrates used to fortify fluid milk, and to determine the influence of vitamin A and D fortification on flavor of milk. The aroma profiles of fourteen (14) commercial vitamin concentrates (vitamins A and D), in both oil soluble and water dispersible forms, were evaluated by sensory and instrumental volatile compound analyses. Orthonasal thresholds were determined for 8 key aroma active compounds in skim and whole milk. Six (6) representative vitamin concentrates were selected to fortify skim and 2% fat high temperature short time (HTST) pasteurized milks (vitamin A at 1500-3000 IU/qt, vitamin D at 200-1200 IU/qt, vitamin A and D at 1000/200-6000/1200 IU/qt). Pasteurized milks were evaluated by sensory and instrumental volatile compound analyses and by consumers. Fat content, vitamin content and fat globule particle size were also determined. The entire experiment was done in duplicate. Water dispersible vitamin concentrates had overall higher aroma intensities and more aroma active compounds detected than oil soluble vitamin concentrates. Trained panelists and consumers were able to detect flavor differences between vitamin A, and vitamin A and D water dispersible fortified skim milks compared to unfortified skim milks. Consumers were not able to detect flavor differences in oil soluble fortified milks but trained panelists documented faint carrot flavor in oil soluble fortified skim milks at the higher vitamin A concentrations (3000-6000 IU). No differences were detected in vitamin D fortified skim milks (P > 0.05) and no differences were detected in all 2% milks (P > 0.05). These results demonstrate that vitamin concentrates may contribute to off flavor(s) in fluid milk, especially in skim milk fortified with water dispersible vitamin concentrates. Objective 3. The extrinsic attributes that drive purchase for milk and plant based alternatives were determined. Subsequently, the personal values to purchase of each beverage type were determinde to give further understanding behind why particular attributes were important. An online conjoint survey was launched with 702 dairy consumers, 172 non-dairy consumers, and 125 consumers of both beverages. Individual means-end chain interviews (MEC) were conducted with fluid milk consumers (D) (n=75), non-dairy alternative consumers (ND) (n=68), and consumers of both beverages (B) (n=78). Fat content (p<0.05) was the most important attribute for dairy milk followed by package size and label claims. Consumers of D preferred 1% or 2% fat content, gallon or half gallon packaging, conventionally pasteurized store brand milk (p<0.05). Sugar level (p<0.05) was the most important attribute for non-dairy beverages, followed by plant source, and package size. Almond milk was the most desirable plant source and half gallon packaging was the most preferred packaging. MEC results suggested that maintaining a balanced diet and healthy lifestyle was important to all consumer groups. Lactose-free was an important attribute for ND and B consumers. A distinguishing characteristic of those who only drank non-dairy alternatives was that plant based beverages contributed to a goal to consume less animal products, beliefs about animal mistreatment, and perceived less environmental impact than fluid milk. Unique to only D consumers was that fluid milk was perceived as a staple food item. These results suggest that the dairy industry should focus on the nutrition value of milk and educating consumers about misconceptions regarding dairy milk. Future beverage innovation should include the development of lactose free milk that is also appealing to consumers in flavor. The change in % milkfat needed to produce a detectable or just noticeable difference (JND) to consumers in skim, 1%, 2%, and whole milks was determined. The second objective was to evaluate how milkfat affected consumer preferences for fluid milk. Threshold tests were conducted to determine the JND for each reference milk (skim, 1%, 2%, and whole milk) with a minimum of 60 consumers for each JND. The JND was determined for milks by visual appearance without tasting and tasting without visual cues. Serving temperature effect (4, 8, or 15?C) on tasting JND values were also investigated. The established JND values were then used to conduct 2-AFC preference tests with milks. Consumers were assigned to three groups based on self-reported milk consumption, skim milk drinkers (n=59), low-fat milk drinkers (consumed 1% or 2% milk, n=64), and whole milk drinkers (n=49). Follow-up interviews were conducted where consumers were asked to taste and explain their preference between milks that showed the most polarization within each consumer segment. Descriptive sensory analysis was performed on the milks used in the follow-up interviews to quantify sensory differences. Visual-only JNDs were lower than tasting-only JND values (P < 0.05). Preference testing revealed three distinct preference curves among the consumer segments. Skim milk drinkers preferred skim milk and up to 2% milkfat but disliked milk higher in fat due to it being "too thick," "too heavy," "flavor and texture like cream," "too fatty," and "looks like half and half." Low-fat milk drinkers preferred 2% milk up to 3.25% (whole milk) but then disliked higher milkfat content. Whole milk drinkers preferred whichever milk was higher in milkfat regardless of how high the fat content went; distinct from skim and low-fat milk drinkers. The findings of this study provide insight on how the industry might adjust milkfat to increase milk preference and remain within the standards of identity of milk.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: McCarthy, K.S., Lopetcharat, K., and Drake, M.A. 2017. Milk fat threshold determination and the effect of milk fat content on consumer preference for fluid milk. J. Dairy Sci. 100:1702-1711.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Lee, A.P., Barbano, D.M., and Drake, M.A. 2017. The influence of ultra pasteurization by indirect heating versus direct steam injection on skim and 2% fat milks. J. Dairy Sci. 100:1688-1701.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: McCarthy, K.S., Parker, M., Ameerally, A., Drake, S.L., and Drake, M.A. 2017. Drivers of choice for fluid milk versus plant based alternatives: what are consumer perceptions of fluid milk. J. Dairy Sci. 100:6125-6138.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Yeh, E., Schiano, A., Jo, Y., Barbano, D.M. and Drake, M.A. 2017. The effect of vitamin concentrates on the flavor of pasteurized milk. J. Dairy Sci. 100:4335-4348.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Yeh, E., Barbano, D.M. and Drake, M.A. 2017. Vitamin fortification of fluid milk. J. Food Sci. 82:856-864.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Park, C.W. and Drake, M.A. 2017. The effect of homogenization pressure on the flavor and flavor stability of whole milk powder. J. Dairy Sci. 100:5195-5205.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: McLean, K.G., Hanson, D., Jervis, S. and Drake, M.A. 2017. Consumer perception of retail pork bacon attributes using adaptive choice conjoint analysis and maximum differential scaling. J. Food Sci. 82:2659-2668
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Stout, M., Park, C.W. and Drake, M.A. 2017. The effect of bleaching agents on the degradation of vitamins and carotenoids in spray dried whey protein concentrate. J. Dairy Sci. 100: 7922-7932.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Schiano, A., Harwood, W., and Drake, M.A. 2017. Sensory analysis of milk. 100 year invited review. J. Dairy Sci. 100:9966-9986
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Carter, B.G., Park, C.W. and Drake, M.A. 2017. Sensitive detection of norbixin in dried dairy ingredients at concentrations of less than 1 part per billion. J. Dairy Sci. 100:8754-8758.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The target audience is the food industry. Foods and food ingredients are widely used in a variety of applications. Consistent sensory quality is required to provide healthy and appealing foods to consumers. An understanding of processing unit operations and how they influence flavor and flavor quality as well as an understanding of consumer behaviors and preferences are necessary. The goal of my research program is to provide actionable ways to document and compare sensory perception of flavor and the role that processing steps play on flavor, flavor stability and flavor quality. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Results have been disseminated to the food industry and other relevant stakeholders through presentations at professional meetings, invited on-site presentations and peer reviewed publications. What do you plan to do during the next reporting period to accomplish the goals?Studies in the forthcoming year will continue to focus on the role of unit operations in processing on flavor formation and how this relates desirable and undesirable flavors. The role of consumer behavior and perception will also be addressed.

Impacts
What was accomplished under these goals? Objectives 1 and 2: Flavor chemistry of fluid wheys and permeates were established and published (see publications). New work was initiated on the flavor chemistry and impact of processing on fluid milk flavor.Raw skim and raw standardized 2% milks (50 L each) were obtained in duplicate on different days and pasteurized at 78°C for 15s (HTST) or 140°C for 2.3s by indirect or direct steam injection ultrapasteurization. Milks were cooled and stored at 4C. Analysis of aroma active compounds was conducted after 0, 3, 7, and 14 days by solid phase micro-extraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Results were analyzed by univariate and multivariate statistics. Forty nine (49) aroma active compounds were identified and quantified in the milks, with differences in profile and relative concentration of volatile compounds. More aroma active compounds and higher relative abundances of sulfur and Maillard reaction volatiles were detected in UP milks compared to HTST milks (p<0.05). Many aroma active compounds decreased in relative abundance in milks with storage (p<0.05). All three milks were distinct in aroma active compounds. The major aroma active compounds in milks were hydrogen sulfide, dimethyl sulfide, 2-butanone, and furfural in indirect UP milks, diacetyl, 3-methyl butanal, dimethyl disulfide, methional, and benzaldehyde in direct steam injection UP milks, and carbon disulfide, 1-octen-3-one, and 1-octen-3-ol in HTST milks, respectively. An understanding of the flavor chemistry of heat treated milk is required to characterize flavor profiles and to identify the source(s) of flavor. Objective 3:The attributes that influence consumers to purchase and consume organic milk were investigated. An Adaptive Choice Based Conjoint (ACBC) survey was designed for attributes of fluid milk. The survey also included Kano, importance and emotions questions for fluid milk, and consumer purchase and attitudes for organic foods. Maximum Difference scaling (MaxDiff) was used to rank the importance of single attributes in fluid milk that affected purchase and to rank issues associated with organic milk. Results were analyzed by univariate and multivariate statistics. A total of 1163 fluid milk consumers completed the survey. Of the organic consumers (N=970), 54.2% reported purchase of organic dairy products on a regular basis, which ranked third behind vegetables (77.3%) and fruits (71.8%). The ideal conventional fluid milk was 2% milkfat, conventionally pasteurized, and contained no additives or label claims. The ideal organic milk was 2% milkfat and conventionally pasteurized, but also contained the label claims "Rbst-free" and "DHA added." Based on utility and importance scores in the ACBC, price was a more motivating factor of purchase for conventional consumers than organic consumers (p<0.05). MaxDiff analysis of organic consumers showed that the belief "organic milk is healthier" was the most important motivator for purchase of organic milk (p<0.05). MaxDiff analysis of all fluid milk consumers confirmed milkfat content as the most important attribute, followed by flavor/taste, package size, and price. Overall (N=1163), milk designation as "organic" was ranked eighth of 14 attributes. Conventional milk consumers (N=193) ranked milkfat as the most important attribute influencing purchase, followed by taste, price, and package size. Organic designation ranked fourteenth of 14 attributes in importance for these consumers. For regular consumers of organic milk (N=526), the most important attributes were milkfat, flavor/taste, and "organic", followed by package size, and price. Better insight into the motivating factors of purchase will enable fluid milk manufacturers to better meet consumer desires. The temporal sensory properties of ready-to-mix (RTM) vanilla protein beverages sweetened with five different sweeteners were investigated using three different temporal methods; Time Intensity (TI), Temporal Dominance of Sensations (TDS), and Temporal Check-All-That-Apply(TCATA).Iso-sweet concentrations for each sweetener (sucralose, sucrose, fructose, stevia, monk fruit) in water and RTM vanilla whey protein beverage at two protein concentrations (15 g or 25 g per 360 mL) were established using magnitude estimation scaling (n=8 panelists, 3 replications). Iso-sweet concentrations were subsequently confirmed in beverages by alternative forced choice (2-AFC) tests (n=40 consumers). Temporal sensory profiling (TI, TDS and TCATA) was then conducted on each beverage in triplicate by a trained panel (n=8). Parameters of maximum intensity, time at maximum intensity, total time, and area under the curve were extracted from TI data. A smoothing function was used to construct curves from TDS and TCATA data to compare dominant attributes among samples. Protein concentration and vanilla flavor had no impact on perceived sweet taste intensity (p>0.05). The three temporal methods provided complimentary results. Results from TI demonstrated that beverages sweetened with fructose or sucrose were characterized by initial intense sweetness that quickly faded. Monk fruit and stevia were slower in sweet onset and characterized by bitter and metallic aftertastes and lingering sweetness. Sucralose displayed a delayed sweetness onset and lingering metallic taste and sweetness after expectoration. By TDS and TCATA, sucrose and fructose beverages were characterized by dominant sweetness. Stevia and monk fruit beverages were characterized by initial dominant sweet taste, then by bitter and metallic. Sucralose beverage was characterized by predominant and lingering sweet taste then metallic. Knowledge of the temporal properties of non-nutritive sweeteners and the methods by which to measure them is important in order to understand how addition into product formulation will affect the overall sensory properties of the food product.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Oltman, A.E., Yates, M.D., and Drake, M.A. 2016. Preference mapping of tomatoes across three stages of consumption. J. Food Sci. 81:S1495-S1505.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Park, C.W. and M.A. Drake. 2016. Condensed milk storage and evaporation affect the flavor of nonfat dry milk. J. Dairy Sci. 99: 9586-9597.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Park, C.W., Stout, M.A., and Drake, M.A. 2016. The effect of spray-drying parameters on the flavor of nonfat dry milk and milk protein concentrate 70%. J. Dairy Sci. 99:9598-9610.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Smith. S., Smith, T.J. and Drake, M.A. 2016. Flavor and flavor stability of cheese, rennet and acid wheys. J. Dairy Sci. 99:3434-4444.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Park, C.W., Parker, M., and Drake, M.A. 2016. The effect of liquid storage on the flavor of whey protein concentrate. J. Dairy Sci. 99:4303-4308.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Smith, T.J., Campbell, R.E., Jo, Y. and Drake, M.A. 2016. Flavor and stability of milk proteins. J. Dairy Sci. 99:4325-4346.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Smith, S., Metzger, L., and Drake, M.A. 2016. Evaluation of whey, milk, and delactosed permeates as salt substitutes. J. Dairy Sci. 99:8687-8698.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Hubbard, E.M., Jervis, S.M. and Drake, M.A. 2016. The effect of extrinsic attributes on liking of cottage cheese. J. Dairy Sci. 99:183-193.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Lawrence, S., Lopetcharat, K., and Drake, M.A. 2016. Preference mapping of soymilk with different U.S. consumers. J. Food Sci. 81: S463-S476.


Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Foods and food ingredients are widely used in a variety of applications. Consistent sensory quality is required to optimize existing markets and to expand into new market segments. Flavor problems (off-flavors or inadequate product understanding or market positioning) cause the food industry billions of dollars every year. Consistent quantifiable ways to document and compare flavor in the industry are lacking. Further, an understanding of the relationship between chemical components and their impact on sensory perception of flavor is lacking. The goal of my research program is to provide quantifiable and applicable ways to document and compare sensory perception of flavor and to further define the role that specific chemical components of food have on sensory perception of flavor. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The results have been disseminated to stakeholders and industry by peer reviewed publications, presentations at national profession and industry meetings and invited presentations. What do you plan to do during the next reporting period to accomplish the goals?Work will continue on investigations into the role of unit operations on dairy foods flavor and consumer perception.

Impacts
What was accomplished under these goals? Objective 1: The flavor and functional characteristics of WPI from Cheddar, Mozzarella, Cottage cheese, and rennet casein whey were compared. WPI were manufactured in triplicate. Powders were rehydrated and evaluated in duplicate by descriptive sensory analysis. Volatile compounds were extracted by solid phase microextraction (SPME) followed by gas chromatography−mass spectrometry (GC-MS). Functional properties were evaluated by measurement of foam stability, protein solubility, and SDS PAGE. WPI from Cheddar and Cottage cheese whey had the highest cardboard flavor while sweet aromatic flavor was highest in Mozzarella WPI. Rennet casein WPI had the lowest overall flavor and aroma. Distinct sour taste and brothy/potato flavor were also noted in WPI from Cottage cheese whey. Consistent with sensory results, aldehyde concentrations were highest in Cheddar and Cottage cheese WPI. Overrun, yield stress, and foam stability were not different (p>0.05) among Cheddar, Mozzarella and rennet casein WPI but WPI from cottage cheese whey had a lower overrun, yield stress and formed a less stable foam (p<0.05). Cottage cheese WPI was more soluble at pH 4.6 compared to other WPI (p<0.05). SDS PAGE results suggested that Cottage cheese WPI had some protein degradation, which likely contributed to functionality differences. This study suggests that WPI produced from non-traditional whey could be used in new applications due to distinct functional and flavor characteristics. The effect of liquid storage on WPC and SMP flavor was determined. For WPC, liquid whey was manufactured and stored, or ultrafiltered to 12% solids and stored. WPC (80% protein) was then spray dried. For SMP, skim milk was concentrated to 30% solids by reverse osmosis (RO) or by evaporation (E) with or without storage prior to evaporation to 50% solids and spray dried. Storage consisted of 4°C for 24 h. Each experiment was replicated three times and included controls that were not stored. Powders (WPC, SMP) were evaluated by sensory and volatile compound analyses. In both WPC and SMP, storage of liquids increased cardboard flavor and decreased sweet aromatic flavor (p<0.05). In unbleached WPC80, storage of liquid whey increased cardboard flavor more than storage of ultrafiltered liquid whey protein; however, storage of bleached ultrafiltered liquid whey protein increased cardboard flavor compared to storage of bleached liquid whey (p<0.05). In both stored and unstored SMP, RO increased sweet aromatic flavor and decreased cardboard flavor intensities compared to E (p<0.05). Volatile compound analyses confirmed increased lipid oxidation products as the source of flavor differences in both WPC and SMP. These results demonstrate that to mitigate off-flavors, for WPC, storage should occur as liquid whey but for storage of bleached product, higher solids minimizes off flavors. For SMP, RO should be used in place of evaporation for production of condensed skim milk. The cooling rate of raw milk may influence sensory properties and pasteurized shelf life. Under the Pasteurized Milk Ordinance (PMO) for Grade A milk, raw milk may be cooled instantaneously by on-farm heat exchangers but is also acceptable if "cooled to 10°C or less within four (4) hours of the commencement of the first milking". The objective of this study was to determine the effect of raw milk cooling on consumer perception and shelf life.Raw milk (18-21°C) was obtained and transported within 1 h of milking to North Carolina State University. After comingling, the batch was split and a plate heat exchanger was used to quickly cool one treatment to <6°C for all milkings. The second treatment was stored in a jacketed bulk tank and slowly cooled over 4 h to <10°C. Three consecutive milkings were collected every 12 h with subsequent milkings added to the previous collections. The bulk milk was kept below 10°C while adding milk for the slow cool milk treatment. After 72 h, each whole milk was separated, pasteurized at 73 or 78°C for 20 seconds, homogenized, and held at 4°C. Difference tests (n=75) and consumer acceptance tests (n=100) were conducted to determine if consumers could detect differences among milks. Descriptive analysis (DA) and microbial testing for aerobic, psychrotrophic, and spore counts were conducted through shelf life. The entire experiment was repeated in triplicate. Raw milks averaged 4.29 Log CFU/mL by aerobic plate count, 52 CFU/mL coliforms, 300,000 SCC and 3.15 ± 0.7% protein. Spores were <20 CFU/mL in raw milk. After processing, consumers could not detect differences (p<0.05) between cooling treatments of the same pasteurization temperature nor between different temperatures of the same cooling treatment. Milks reached sensory failure 35-42 days after processing, and aerobic counts were between 5-7 log cfu/ml. Higher pasteurization temperature decreased shelf life. Cooling treatment had no effect on shelf life. These results suggest that pasteurized milk quality is due to a combination of many factors. Raw milk cooling rate is not the largest impact on milk quality.

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Li, X., Lopetcharat, K., Qiu, Y., and Drake, M.A. 2015. Sugar reduction of skim chocolate milk and viability of alternative sweetening through lactose hydrolysis. J. Dairy Sci. 98:1455-1466.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Li, X.E., Jervis, S.M. and Drake, 2015. Examining extrinsic factors that influence product acceptance: A review. J. Food Sci. 80:R901-909.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Li, X.E. and Drake, M.A. 2015. Sensory perception, nutritional role, and challenges of flavored milk for children and adults. J. Food Sci. 80:R665-670.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Jervis, M., Smith, T.J., and Drake, M.A. 2015. The influence of solids concentration and bleaching agent on bleaching efficacy and flavor of sweet whey powder. J. Dairy Sci. 98:2294-2302.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Li, X.E., Lopetcharat, K., and Drake, M.A. 2015. Parents and childrens acceptance of skim chocolate milks sweetened by monk fruit and stevia leaf extracts. J. Food Sci. S1083-1092.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Qiu, Y., Smith, T.J., Foegeding, E.A. and Drake, M.A. 2015. The effect of microfiltration on color, flavor and functionality of 80% whey protein concentrate. J. Dairy Sci. 98:5862-5873.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Oltman, A.E., Lopetcharat, K., Bastian, E., and Drake, M.A. 2015. Identifying key attributes for protein beverages. J. Food Sci. S1383-S1390.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Smith, T.J, Gerard, P.D., and Drake, M.A. 2015. Effect of temperature and concentration on benzoyl peroxide bleaching efficacy and benzoic acid levels in whey protein concentrate. J. Dairy Sci. 98: 7614-7627.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Smith, T.J., Foegeding, E.A., and Drake, M.A. 2015. Sensory and Functionality Differences of Whey Protein Isolate Bleached by Hydrogen or Benzoyl Peroxide. J. Food Sci. C2153-C2160.


Progress 11/07/13 to 09/30/14

Outputs
Target Audience:The target audience is the food industry. Foods and food ingredients are widely used in a variety of applications. Consistent sensory quality is required to optimize existing markets and to expand into new market segments. Flavor problems (off-flavors or inadequate product understanding or market positioning) cause the food industry billions of dollars every year. Consistent quantifiable ways to document and compare flavor in the industry are lacking. Further, an understanding of the relationship between chemical components and their impact on sensory perception of flavor is lacking. The goal of my research program is to provide quantifiable and applicable ways to document and compare sensory perception of flavor and to further define the role that specific chemical components of food have on sensory perception of flavor. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Results have been disseminated to the food industry and other relevant stakeholders through presentations at professional meetings, invited on-site presentations and peer reviewed publications. What do you plan to do during the next reporting period to accomplish the goals?Studies in the forthcoming year will continue to focus on the role of unit operations in processing on flavor formation and how this relates to off flavors as well as desirable flavors in fluid milk, cheeses and dried dairy ingredients. The role of consumer perception and how consumers perceive food extrinsic and intrinsic parameters as well as priming statements will also be invstigated.

Impacts
What was accomplished under these goals? Objectives 1 and 2. Flavor and flavor stability among cheese, rennet and acid wheys was investigated. Full-fat and fat-free Cheddar, rennet and acid casein, cottage cheese, and Greek yogurt fluid wheys were manufactured in triplicate. Volatile compound and descriptive sensory analyses were evaluated on liquid wheys initially and after 24 and 48 h. Fresh wheys displayed sweet aromatic and cooked milk flavors. Cheddar wheys were distinguished by diacetyl/buttery flavors and acid wheys (acid casein, cottage cheese, and Greek yogurt) by sour aromatic flavor. Acid casein and cottage cheese wheys displayed soapy flavor, Greek yogurt whey had a distinct potato flavor and acid casein also displayed brothy and animal flavors. Cardboard flavors increased and sweet aromatic and buttery flavors decreased with storage in all wheys. Volatile compound profiles were distinct among wheys (p<0.05), consistent with sensory results. Lipid oxidation aldehydes increased in all wheys with storage time and increased in the order Cheddar > fat free Cheddar > acid > rennet wheys. These results provide baseline information for the viability of processing underutilized wheys into value-added ingredients. The effect of pH induced milk fat globule membrane aggregation (pH 4.2, 5.2) and microfiltration on norbixin levels in colored liquid Cheddar whey was investigated. Cheddar cheese whey was manufactured from colored, pasteurized milk and subsequently pasteurized and fat separated. Liquid whey was subjected to one of four treatments: control (no treatment), pH 4.2 (acidification with hydrochloric acid (HC), and centrifugation to remove precipitate), pH 5.2 (acidification with HC, and centrifugation to remove precipitate), or microfiltration (MF). Proximate analyses of whey were conducted using standard methods. Norbixin content was determined by HPLC. The protein compositions of liquid whey before and after treatments were evaluated by polyacrylamide gel electrophoresis (SDS-PAGE). The experiment was replicated 3 times and analysis of variance was conducted to identify differences. Norbixin was decreased by 49, 40, and 46% for pH 4.2, pH 5.2, and MF treatments, respectively (p<0.05). No differences were detected in protein and mineral content among liquid wheys. SDS-PAGE gels also showed no visible differences in main whey protein (alpha-lactalbumin and beta-lactoglobulin) bands between control and pH 4.2 and 5.2 and MF wheys. Based on color reduction and protein content, pH reduction of norbixin and/or microfiltration could be used as novel methods to remove annatto from Cheddar whey. The impact of production run time on sensory, microbiological, and functional properties of SMP was evaluated. Six different domestic spray drying facilities were selected for sampling of low and medium heat SMP. Samples taken were milk concentrate from the last evaporator effect (50% solids) and the spray dried powder after 0, 12, 24, and 36 h production run time. Microbiological and flavor properties (sensory and instrumental volatile analyses) were performed on both the concentrated milk and powder. Coliforms, aerobic bacteria, and aerobic thermophilic sporeformers were enumerated. Surface free fat, particle size, solubility, viscosity, furosine, and whey protein nitrogen index (WPNI) were also evaluated. Results were consistent across facilities (0>0.05). Increased production run time increased aroma and cooked/sulfur flavor intensities and decreased sweet aromatic flavor in SMP (p<0.05). Volatile compound results were consistent with sensory profiles with higher sulfur volatiles and decreased sweet aromatic compounds (2 acetyl pyrroline, ethyl maltol) with increased run times. Microbial counts (aerobic thermophilic spores, total aerobic plate counts) increased (p<0.05) and solubility also decreased with run time. Particle size, viscosity, and furosine were not affected by production run time (p>0.05). This study demonstrates that as the production run time increases, sensory, microbial, and functional quality of SMP deteriorates. Objective 3. The attributes of fresh market tomatoes that influence consumer preference were identified. Three focus groups were conducted to explore how consumers perceived tomatoes. Subsequently, an Adaptive Choice Based Conjoint (ACBC) survey was conducted to understand consumer preferences towards traditional red tomatoes. The ACBC survey explored the importance of color, firmness, size, skin, texture, interior, seed presence, flavor and health benefits. The most important tomato attribute was color, then juice when sliced, followed by size, followed by seed presence, which was at parity with firmness. An attractive tomato was red, firm, medium/small sized, crisp, meaty, juicy, flavorful and with few seeds. Deviations from these features resulted in a tomato that was rejected by consumers. An organic or farmers' market label was an attractive feature, but if not present, did not decrease the acceptability of that tomato. Sugar reduction in skim chocolate milk among children was investigated. Skim chocolate milks (SCM) witsix different sucrose concentrations (205, 142.2, 86.6, 52.7, 32.1, and 17.14 mM, 205mM was iso-sweetness level of a commercial product) were first manufactured and evaluated by young adults (19-35 y, n=146). Three or five sucrose concentrations (205, 162, 140.6, 126, and 86.6 mM) were then selected for chocolate milk testing with children (3 milks for 5-7 y (n=49), 5 milks for 8-13 y (n=104)). Children evaluated overall and sweet taste liking on a 7-point smiley face scale (1=super bad, 7=super good) and data were evaluated by analysis of variance with means separation. Overall liking scores (OVL) of SCM were not different (p>0.05) between milks with sucrose concentration 140.6 mM and 205 mM for 5-7 y and 8-10 y (n=104), and both sucrose levels of SCM scored higher compared to 86.6 mM (p<0.05). Differences for OVL and sweetness liking were observed between 205 mM and 162 mM (p<0.05) for 11-13 y (n=53) but not between 162 and 140.6 mM (p>0.05). SCM with 140.6 mM sucrose received an overall liking score of 4.9/7 (5=good). The results demonstrate that up to 31% sugar reduction in chocolate milk is possible for children ages 5-13 y and older children had more distinct preferences than younger children. U.S. and Irish consumer preferences of Cheddar cheeses manufactured in the U.S. and Ireland were compared. Descriptive analysis with a highly trained panel and an established Cheddar cheese sensory language was conducted in triplicate on 37 aged Cheddar cheeses (13 U.S., 24 Irish). Representative cheeses (n=9) were selected for consumer testing in Cork and Dublin, Ireland and in Raleigh, NC, U.S. (n=150 each location). Irish Cheddars were characterized by caramel and nutty flavors with low intensities of grassy and barny flavors while U.S. Cheddars were high in sulfur and brothy flavors. Both Dublin and U.S. consumers generally liked mild cheese flavors, whey and cooked/milky, while Cork consumers had strong preferences toward aged and country-specific flavors, brothy, caramel and barny flavors and more intense basic tastes. There were not country-specific likes or dislikes for Cheddar cheese flavors (p>0.05).

Publications

  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Park, C.W., Bastian, E., Farkas, B.E., and Drake, M.A. 2014. The effect of feed solids concentration and inlet temperature on the flavor of spray dried whey protein concentrate J. Food Sci. 79:C19-C24.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Campbell, R.E., Gerard, P.D., Drake, M.A. 2014. Characterizing endogenous and exogenous peroxidase activity for bleaching of fluid whey and retentate J. Dairy Sci. 97:1225-1232.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Campbell, R.E., Boogers, I., Drake, M.A. 2014. Development of a novel method for the extraction of norbixin from whey and its subsequent quantification via high performance liquid chromatography. J. Dairy Sci. 97: 1313-1318.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Jervis, S.M., Jervis, M., Guthrie, B. and Drake, M.A. 2014. The efficacy of using photographs to represent attributes of sliced sandwich bread in an adaptive choice based conjoint. J. Sensory Stud. 29:64-73.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Park, C.W. and Drake, M.A. 2014. The distribution of fat in dried dairy particles determines flavor release and flavor stability. J. Food Sci. 79:R452-459.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Smith, T.J. Li. X.E., Drake, M.A. 2014. Norbixin and bixin partitioning in Cheddar cheese and whey. J. Dairy Sci. 97:332-3327.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Campbell, R.E and Drake, M.A. 2014. Enzymatic bleaching in commercial colored Cheddar whey retentate. Int. Dairy J. 38:148-153.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Jervis, S.M., Gerard, P.D., Drake, S., Lopetcharat, K., and Drake, M.A. 2014. The perception of creaminess in sour cream. J. Sensory Stud. 29: 248-257.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Li, X., Lopetcharat, K., and Drake, M.A. 2014. Extrinsic attributes that influence parents's purchase of chocolate milk for their children. J. Food Sci. 79: S1407-S1415
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Park, C.W., Bastian, E., Farkas, B.E., and Drake, M.A. 2014. The effect of acidifcation of liquid whey protein concentrate on the flavor of spray dried powder. J. Dairy Sci. 97:4043-4051.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Jervis, M.J. and Drake, M.A. 2014. The use of qualitative research methods in quantitative science: a review. J. Sensory Stud. 29: 234-247.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Frankowski, K.M., Miracle, R.E. and Drake, M.A. 2014. The role of sodium in the salty taste of permeate. J. Dairy Sci. 97:5356-5370.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Jervis, M.J., Jervis, S.M., Guthrie, B. and Drake, M.A. 2014. Determining children's perceptions, opinions, and attitudes for sliced sandwich breads. J. Sensory Stud. 29: 234247.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Oltman, A.E., Jervis, S.M., and Drake, M.A. 2014. Consumer attitudes and preferences for fresh market tomatoes. J. Food Sci. 79: S2091-S2097.