INVESTIGATION OF FOOD SAFETY, STORAGE STABILITY, NUTRITIONAL, TEXTURAL AND SENSORY CHARACTERISTICS OF GOAT MILK POWDER AND CHEESE PRODUCTS DURING EXTENDED STORAGE.

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: EVANS-ALLEN
• Reporting Frequency: Annual
• Accession No.: 1009424
• Project No.: GEOX-3225
• Project Start Date: May 3, 2016
• Project End Date: Mar 31, 2021

Project Director
Park, YO, W.

Recipient Organization
FORT VALLEY STATE UNIVERSITY
1005 STATE UNIVERSITY DRIVE
FORT VALLEY,GA 31030

Performing Department
Animal Science

Non Technical Summary
The presence of harmful microorganisms in milk and dairy products is of great concern for food safety of the public. Most disease outbreaks of dairy products have stemmed from raw, improperly pasteurized milk, post-pasteurization contamination during and after manufacture, and during storage of the products. Longer and improper storage conditions deteriorate shelf-life of dairy products due to possible bacterial growth, off- flavor development by proteolysis, lipolysis, lipid oxidation, and textural and sensory quality degradations. In this project, the studies will focus on the investigation of food safety, storage stability, nutritional, textural and sensory characteristics of goat milk powder and cheese products during extended storage periods. The proposed project has five major goals: (1) To assess food safety of two types of powdered goat milk (whole and skim) by examining the survival of E. coli O157:H7 in the low aw powdered goat milk stored at two temperatures (4oC and 25oC) during three storage periods (0, 3 and 6 months), (2) To evaluate storage stability of the powdered goat milk (control vs. E. coli inoculated) by determining water activity, pH, fatty acids and lipid oxidation for the three storage periods, (3) To develop iron (Fe) fortified goat milk cheeses, and compare basic nutrients, iron and fatty acid compositions between control and Fe fortified cheese groups, (4) To determine storage stability of the two cheese groups in water activity, lipid oxidation, lipolysis and proteolysis, and (5) To examine textural and sensory characteristics of the two goat cheese groups for the same storage treatments. Specific collaborative arrangements have been made with the USDA/ARS, Eastern Regional Research Center, the University of Georgia, Athens, and North Carolina State University, Raleigh, NC to ensure that the research will be conducted and undertaken with due consideration to its ultimate utility and application. The outcomes of this project will accomplish the NIFA's priority areas such as (i) food safety, (ii) sustainable agriculture of rural communities for 21st century, and (iii) global food security and hunger through the development of dairy products and their quality evaluation. The outcomes of these investigations will also provide essential information on food safety, storage stability and consumer acceptability of dairy goat products, which can promote the profitability and sustainability of the dairy goat industry.

Animal Health Component

0%

Research Effort Categories

Basic

40%

Applied

40%

Developmental

20%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
502	3450	2000	100%

Knowledge Area
502 - New and Improved Food Products;

Subject Of Investigation
3450 - Milk;

Field Of Science
2000 - Chemistry;

Keywords

food safety

storage stability

textural

sensory properties

goat milk powder

goat cheeses

Goals / Objectives
The proposed project has five major goals: (1) To assess food safety of two types of powdered goat milk (whole and skim) by examining the survival of E. coli O157:H7 in the low aw powdered goat milk stored at two temperatures (4oC and 25oC) during three storage periods (0, 3 and 6 months), (2) To evaluate storage stability of the powdered goat milk (control vs. E. coli inoculated) by determining water activity, pH, fatty acids and lipid oxidation for the three storage periods, (3) To develop iron (Fe) fortified goat milk cheeses, and compare basic nutrients, iron and fatty acid compositions between control and Fe fortified cheese groups, (4) To determine storage stability of the two cheese groups in water activity, lipid oxidation, lipolysis and proteolysis, and (5) To examine textural and sensory characteristics of the two goat cheese groups for the same storage treatments.

Project Methods
Experimental methods and procedureswill beperformed as following descriptions: Experimental goat milk products of powder milk and iron fortified and controlcheeses will be prepared at the Georgia Small Ruminant Research and Extension Center (GSRREC), Fort Valley State University, Fort valley, GA, USA.A. Preparation of whole and skim goat milk powders (1) Three lots of whole milk and 3 lots of skim milk powders will be produced by spray drying method, using a laboratory model of the spray dryer (FT80 Tall Form, Armfield, Hamphire, England). The whole goat powdered products may also be purchased from local retail outlets. (2) Three batches of skim goat milk powder will be produced by using the same spray dryer. The skim fluid milk will be prepared by separating cream from the fluid whole goat milk using a cream separator (Model 17584, Clair Co., Althofen, Austria).B. Experimental design for powdered goat milk studiesFor the investigation on growth and survival of pathogens in powdered goat milk, the study will be conducted in 3 x 2 x 3 factorial experiment. Three batches of whole goat milk powders will be used in two separate studies. Because of the possible danger of the E. coli O157:H7 bacteria in the environment, the Escherichia coli K12 which possess the same microbial properties will be used in the actual experiment instead. The evaluation of storage stability and the survivability of Escherichia coli K12 in the dehydrated goat milk will be examined at two storage temperatures (4oC and 25oC) and three storage periods (0, 2, and 4 months).C. Preparation of pathogen inoculated and control powder goat milk samplesThe pathogen growth and survival study will be carried out for 0, 2, and 4 month storage periods. For the pathogen treated group, Escherichia coli K12 will be inoculated into milk powder, and then survival of the bacteria will be determined using a modified method of Deng et al. (1998).D. Manufacture of iron fortified goat milk cheeses and their study(1) Manufacture of iron fortified and control goat cheeses: For the manufacture of iron fortified goat cheeses, iron in ferrous sulfate form will be added to goat milk before cheesemaking by using the procedures of Zhang and Mahoney (1991). Three batches of Cheddar-type goat milk cheese will be manufactured using the procedures of Kosikowski (1977). Two different levels of iron as FeSO4 will be added into pasteurized goat milk. Control cheeses without iron fortification will also be made as reference control for each batch,and stored until analysis at 4oC.(2) Experimental design for iron fortified goat cheese study: This study will be conducted in a 3 x 3 x 3 factorial experiment. The three batches of manufactured experimental goat cheeses will be stored at 3 different storage temperatures (4°C, 22°C, and -18°C) and three different storage periods (0, 3, and 6 months). All cheese samples will be subject to respective treatments immediately after manufacture. All cheese samples will be cut into 3 x 3 x 5 inch sizes blocks, and individually vacuum packaged in a plastic pouch (Koch Inc. Kansas City, MO) before placing them in the designated storage treatment. At each storage period, all cheese samples in triplicates will be analyzed for chemical analysis, water activity, fatty acid analysis, lipid oxidation, textural analysis, and sensory evaluation. Proteolysis and lipolysis of all samples will be also evaluated for storage stability of the experimental cheese samples.E. Chemical analyses:.(1) Basic nutrient analyses: Protein, fat, carbohydrate, ash and total solids contents of all experimental goat milk samples will be analyzed by AOAC (1990) methods. For fat analysis of cheese samples may be also analyzed using Bobcock procedure, while powder milk samples may be analyzed by ether extraction method. (2)pH analysis by a pH meter (Accumet No. 910; Fisher Scientific, Pittsburgh, PA, USA). (3) Fatty acid analysis: Fat will be extracted usingthe standard method from the AOCS (1975), and Fatty Acid Methyl Esters (FAME) will be prepared for fatty acids analysis using a Thermo Electronic (Austin, TX, USA) GC-MS (Model TRACE GC Ultra) equipped with flame ionization detector (FID) and an auto sampler (Model AS-3000, Thermo Electronic Co.). Fatty acids will be quantified by a fused silica capillary column (0.25-mm i.d. x 0.25µm film thickness, x 60-m; SP-2380 Supelco, Inc., Bellefonte, PA, USA).F. Measurement of water activity (aw): Water activity will be measured at room temperature using an AquaLab Aw meter. Approximately 2 g of powder milk sample will be placed into the measuring cup and loaded into the water activity meter. The estimation of water activity as well as temperature will be carried out by the AquaLab Aw meter.G. Evaluation of lipid oxidation: (1) Peroxide Value will be determined using a method described by AOAC (1975). Lipid will be extracted from powder milk using Folch et al.(1957) method. (2)p-Anisidine Value will be determined by AOCS (1975) Cd 18-90 procedure. (3) ToTox Value (the total oxidation value) of a samplewill be estimated by the combined values of peroxide value and p-anisidine value, whichmeansToTox value = 2 POV + p-AnV.H. Microbiological assay: (1) Assays of different types of microbes: The background microbes will be checked using 10 g of samples from each control vial, at the initial and final storage periods (0 and 4 months). If background microbial growth occurs, it can affect the survival of the inoculated bacteria. Aerobic plate count (APC), E.coli/coliform, and yeast/mold will be determined by 3M petrifilm technique. A 10 g control sample will be combined with 90 mL buffered peptone water (0.1%) in a Stomacher bag, and pummeled in the Stomacher 400 circulator for 1 minute. One mL of the sample in duplicate will be pipetted onto the three different types of 3M petrifilm plates. (2) Enumeration and Inoculation of Escherichia coli into powder milk: Escherichia coli K12 will be used for experimentation instead of the pathogenic Escherichia coli O157:H7 for safety purposes. Prior to inoculation, enumeration of the initial concentration of inocula will be performed by plating on 3M petrifilm in duplicate, along with serial dilution (1:10, 0.1% peptone water) and plating on 3M petrifilm plates.I. Evaluation of lipolysis and proteolysis of stored cheeses: (1) Proteolysis: The extents of protein degradation of the experimental goat milk products will be determined by water soluble nitrogen (WSN) content using the method of Jin and Park (1995). (2)Lipolysis: The degrees of lipolysis of all experimental yogurt samples will be analyzed by acid degree value (ADV) using the procedure of Richardson (1985).J. Textural and sensory analysis: (1)Textural characteristics of the ice cream will be evaluated using a texture analyzer (TA-XT2 Texture Technologies Corp., Scarsdale, NY, USA).(2) Sensory Evaluation: An eight member sensory panel composed of faculty and graduate students from College of Agriculture, Family Sciences and Technology at Fort Valley State University, Fort Valley, GA will evaluate the sensory properties of goat milk ice creams. Panelists will assess the flavor, body and texture, and color and appearance properties of the goat milk cheese products using the USDA scorecard (1976) and ADSA Collegiate Dairy Products Evaluation scorecard.K. Statistical Analysis: All experimental data collected from the microbial food safety, storage stability, lipid oxidation and water activity of powder goat milk studies, as well as iron fortified cheese studies of nutritional composition, storage stability, lipolysis, proteolysis, textural and sensory properties will be analyzed for analysis of variance, correlations between parameters, and least squares means and Duncan's multiple mean comparison by Steel and Torrie (1960). All data will be also analyzed usingGLM of SAS program (2004).

Progress 05/03/16 to 03/31/21

Outputs
Target Audience:The target audiences of this research project ondairy products (i.e., cheese, yogurt, and powder milk, etc.) include consumers, dairy product manufacturers, food safety inspectors, food products distributors and retailers, food scientists, food microbiologists, sensory scientists, nutritionists, milk producers and dairy goat farmers in the state of Georgia, US and around the world. The specific audiences would be the health conscious consumers, who are looking for hypoallergenic, healthier and better quality of microbiological, nutritional, textural and sensory characteristics of dairy goat products. Changes/Problems:The project hasexpired on March 31st, 2021, and no additional changes areneeded. What opportunities for training and professional development has the project provided?The physicochemical properties of the three different species milk cheesesstored under different storage treatments of time and temperatures were anlayzed in the laboratories.The experimental data were statistically analyzed and utilized for completion of a graduate student's thesis project. These projectresearch data has been published as an M.S. thesis. How have the results been disseminated to communities of interest?The outcomes of the final year of thisresearch projectwere organized and published in tworefereed journals such as MDPI Dairy journal and Journal of Dairy Science, and also presented at annual national scientific conferences, including theInstitute of Food Technologists (IFT) and American Dairy Science Association (ADSA). What do you plan to do during the next reporting period to accomplish the goals?There is no additionalplan for this project, since the project periodended on March 31st, 2021.

Impacts
What was accomplished under these goals? The fifth objective of the proposed project was studied todeterminethe storage stabilities offive different varieties of goat, cow and sheep milk cheeseswith regard to water activity, lipid oxidation, fatty acidcomposition, lipolysis and proteolysis. The domestic varieties of goat and cow milk cheeses were compared withimported sheep milk cheeses in these physicochemical characteristics underdifferent storage periods and temperature treatments.The physicochemical properties of three species milkcheeseswere anlayzed, and the data were compared for the differences in proteolysis and lipolysis occurringduring the storage period. In addition, the outcomes of this part of the research project were published in tworefereed journals, and also presented at annual national scientific conferences, including theInstitute of Food Technologists (IFT) and American Dairy Science Association (ADSA).

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Paswan, R. and Y.W. Park. 2020. Survivability of Salmonella and Escherichia coli O157:H7 pathogens and food safety concerns on commercial powder milk products. Dairy 1(3):189-201. MDPI. doi.org/10.3390/dairy1030014
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Paswan, R., A. Mishra and Y.W. Park. 2020. Survivability of Salmonella pathogens and physicochemical characteristics of powder goat milk stored under different storage treatment regimens. Dairy 2020, 1, 269283; doi:10.3390/dairy1030018
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Park, Y.W. and G.F. W. Haenlein. 2021. A2 Bovine Milk and Caprine Milk as a Means of Remedy for Milk Protein Allergy. Dairy 2021, 2(2), 191-201; https://doi.org/10.3390/dairy2020017
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2021 Citation: Paswan, R. and Y.W. Park. 2021. Textural characteristics of different varieties of commercial cow and goat milk cheeses stored under different temperature and time treatments. J. Dairy Sci. 104. (Suppl. 1): Paper # 209.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2021 Citation: Paswan, R, A. Singh and Y.W. Park. 2021. Comparison of lipolytic and proteolytic patterns of commercial cow, goat and sheep milk cheeses during 6 months refrigerated and frozen storage. J. Dairy Sci. 104. (Suppl. 1): Paper # 179.
• Type: Conference Papers and Presentations Status: Accepted Year Published: 2021 Citation: Paswan, R. and Y.W. Park. 2021. Evaluation of fatty acid profiles of domestic and imported varieties of cow, goat and sheep milk cheeses stored under different treatment regimens. J. Dairy Sci. 104. (Suppl. 1): Paper # 178.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:The target audiences of this research project are dairy product(i.e., powder milk and cheese) consumers, dairy productmanufacturers, food safety inspectors, food products distributors and retailers, food scientists, food microbiologists, sensory scientists, nutritionists, milk producers and dairy goat farmers in the state of Georgia, US and around the world. The specific audiences would be the health conscious consumers, who are looking for hypoallergenic, healthier and better quality of microbiological, nutritional, textural and sensory characteristics of dairy goat products. Changes/Problems:There will be no changes/problems for this final year of this project. Thanks to the recently established electron microscopy laboratory at Fort Valley State University, this project has provided the PI with an excellent opportunity for training and evaluation of microstructures of control and iron fortified goat milk Cheddar cheeses, which was not the originally planned objective of the project. What opportunities for training and professional development has the project provided?This project has provided the graduate studentwith excellent training opportunities to become a good dairy/food scientist inevaluation of nutritional, microbiological, chemical and sensory characteristics of goat milk Cheddar cheese products. The study was also focused on the evaluation of the microstructure of iron fortified caprine milk Cheddar cheeses through evaluation of microstructures, iron contents and iron foci of the fortified cheeses, water activity, pH, fatty acids and lipid oxidation of the experimental cheeses atdifferent storage temperatureand period treatments. How have the results been disseminated to communities of interest?The research dataof this 4thyear research project have been analyzedstatistically using SAS statistical packages. The resultant outcomes of the researchhave beendisseminated toprofessional societyjournals such asjournal of food science and dairy science.The major areas of dissemination werefood chemistry, dairy technology, storage stability, rheology and sensory science as well asmarketing of iron fortified goat milk cheeses. The research data were also presented atnational and international conferences in food science, nutritionand dairy science disciplines. What do you plan to do during the next reporting period to accomplish the goals?As the final phase of the proposed project, the experimental goat cheeses will be examined and compared for textural and sensory characteristics oftwo goat cheese groups. All experimental data for the past four years will be compiled and organized for comparison, especially focusing oniron fortified goat milk Cheddar cheeses relative to non-fortified control cheeses. In addition, the study results on the powder goat milk will be summarized and compared with goat milk cheese data.

Impacts
What was accomplished under these goals? The fourthobjective of the proposed project was conducted onevaluation of water activity, lipid oxidation, fatty acid composition, lipolysis and proteolysis on the control and iron fortified goat cheeses.The data were anlayzed, and utilized for completion of a graduate student'sthesis project. The student's research data has been published as an M.S. thesis. In addition, the outcomes of this part of the research project were published in a few refereed journals, and also presented at national conferences such as Institute of Food Technologists (IFT) and American Dairy Science Association (ADSA).

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Park, Y.W. 2020. The impact of plant-based non-dairy alternative milk on the dairy Industry. Food Sci Anim Resour. pISSN: 2636-0772: doi.org/10.5851/kosfa.2020.e82
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Haenlein, G.F.W. and Y.W. Park. 2020. Fighting the Deadly Helminthiasis without Drug Resistance. Dairy 1(3): 177-186. MDPI. doi.org/10.3390/dairy1030012
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Renchinkhand, G., S-H, Cho, Y. W. Park, G-Y, Song, and M. S. Nam. 2020. Biotransformation of major Ginsenoside Rb1 to Rd by Dekkera anomala YAE-1 from Mongolian fermented milk (Airag). J. Microbiol. Biotechnol. 30(10): 1536-1542. https://doi.org/10.4014/jmb.2004.04022
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Paswan, R., A. Siddique, A. Mishra, and Y. W. Park., 2020. Profiles of fatty acid composition in relation to water activity of powder goat milk stored under different storage time and temperature. J. Dairy Sci. 103 (Suppl. 1), pp 221.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Paswan, R., A. Mishra, and Y. W. Park., 2020. Survivability of Salmonella pathogens in powder goat milk stored under refrigeration and room temperatures for 6 months. J. Dairy Sci. 103 (Supplement 1), pp 272.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:The target audiences of this research project are dairy products (i.e., powder milk and cheese) consumers, dairy products manufacturers, food safety inspectors, food products distributors and retailers, food scientists, food microbiologists, sensory scientists, nutritionists, milk producers and dairy goat farmers in the state of Georgia, US and around the world. The specific audiences would be the health conscious consumers, who are looking for hypoallergenic, healthier and better quality of microbiological, nutritional, textural and sensory characteristics of dairy goat products. Changes/Problems:The evaluation of microstructures of control and iron fortified goat milk Cheddar cheeses wasan addition to the originally planned objective of the project. The recently established electron microscopy laboratory at Fort Valley State University has made this GEOX-3225 project enable us to investigatethe microstructures of the iron fortified and non-fortified cheeses. This condition has enhancedthe research capacity of the PI in conduction of a deeper level of studies concerning the evaluation of microstructures of the goat milk cheeses during extended storage period at two different storage temperature conditions. What opportunities for training and professional development has the project provided?The project has providedtwo graduate students withtraining opportunities for evaluation of nutritional, microbiological, chemical and sensory characteristics of goat milk Cheddar cheeseproducts. The study was focused on the evaluation of the microstructure of iron fortified caprine milk Cheddar cheeses through evaluation of microstructures, iron contents and iron foci of the fortified cheeses,water activity, pH, fatty acids and lipid oxidation of the experimental cheeses for different storage temperatures and storage periods. How have the results been disseminated to communities of interest?The generated research outcomes of this 3rd year researchproject have been compiled,statistically analyzed and disseminated to the professional scientific communities of food science and dairy science, includingfood chemistry, dairy processing, dairy technology, storage stability, sensory science and marketing of iron fortified goat milk cheeses. The research data were disseminated bypublications of refereed journal as well as national and international conferences in food science, rheology and dairy science disciplines. What do you plan to do during the next reporting period to accomplish the goals?The subsequent extensive experiments will be conducted oniron fortified goat milk Cheddar cheeses bydeterminingstorage stability of the two cheeses (iron fortifed vs. non-fortified)groups in water activity, lipid oxidation, lipolysis and proteolysis.

Impacts
What was accomplished under these goals? The third objective of the proposed project was conducted, the experiments were completed, and agraduate student has accomplished histhesis project. The student's research data has been published as an M.S. thesis. In addition,the outcomes of this part of the research project were reported in refereed journals, and alsopresented at national conferences such as Institute of Food Technologists (IFT) and American Dairy Science Association (ADSA).

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Siddique, A. and Y. W. Park, 2019. Effect of iron fortification on microstructural, textural and sensory characteristics of caprine milk Cheddar cheeses under different storage treatments. J. Dairy Sci. Vol. 102:2890-2902. https://doi.org/10.3168/jds.2018-15427
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Siddique, A. and Y. W. Park, 2019. Evaluation of correlation between acid degree value and peroxide value in lipolysis of control and iron fortified caprine milk cheeses during 4 months storage. Open J. Animal. Sci. 9:1-11. DOI: 10.4236/ojas.2019.91001
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Nam, M.S., J.H. Nam, H.C. Bae, G. Renchinkhand, Y.W. Park, 2019. Physicochemical properties of rice powder added camembert cheese during 4 weeks ripening. Adv Dairy Res. 7:229. doi: 10.35248/2329-888X.19.7.229.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Park, Y.W., J. O. Oglesby, S.A. Hayek, S.O. Aljaloud, R. Gyawali and S.A. Ibrahim. 2019. Impact of different gums on textural and microbial properties of goat milk yogurts during refrigerated storage. Foods. 8:169; doi:10.3390/foods8050169.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Siddique, A. and Y.W. Park. 2019. Fatty acid profiles of control and iron fortified caprine milk Cheddar cheeses stored under different time and temperature. J. Dairy Sci. Vol. 102. Suppl. 1. Abstract #M71. Page 33.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Siddique, A. and Y.W. Park. 2019. Unique characteristics of lauric to capric fatty acid ratios in control and iron fortified caprine milk Cheddar cheeses under different storage treatment regimens. IFT Abstract No. EP-004. New Orleans, LA.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Park, Y.W. and A. Siddique. 2019. Effect of iron fortification on rheological and sensory characteristics of caprine milk Cheddar cheese. IGA Asian Regional Conference on Goats.Abstrct. #116. Chitwan, Nepal. Oct. 20-23.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audiences of this research project are diary products (i.e., powder milk and cheese) consumers, dairy products manufacturers, food safety inspectors, food products distributors and retailers, food scientists, food microbiologists, sensory scientists, nutritionists,milk producersand dairy goat farmers in the state of Georgia, US and around the world. The specific audiences would be the health conscious consumers, who are looking for hypoallergenic,healthier and better quality of microbiological, nutritional, textural and sensory characteristics of dairy goat products. Changes/Problems:Commercial fullfat powder goat milk products will be continuously used in thisstudy, because the originally planned equipment (the spray dryer) has been non-functional. All study parameters will be evaluated as same as this year. What opportunities for training and professional development has the project provided?The project has supported two graduate students for MS degree research, and provided the studentswith training opportunities forevaluation of nutritional, microbiological, chemicaland sensory characteristicsof powder milk products. The study was focused on theevaluation ofstorage stability inpowdered goat milk (control vs.E. coliinoculated) by determining water activity, pH, fatty acids and lipid oxidation for the three storage periods. How have the results been disseminated to communities of interest?The researchresults of this part of the projecthave been disseminated to the scientific communities of food science and dairy science, such as food microbiology, food chemistry, dairy processing, dairy technology, storage stability, sensory scienceand marketing of dehydrated products.The research data were disseminated through thepublications of refereed journal as well as national and international conferences in food science, microbiology and dairy science disciplines. What do you plan to do during the next reporting period to accomplish the goals?The next study willfocuson the development ofiron (Fe) fortified goat milk cheeses, and make comparison ofbasic nutrients, iron and fatty acid compositions between non-fortified control and Fe fortified cheese groups.

Impacts
What was accomplished under these goals? The secondobjective of the proposed project was accomplished, and the experiments were conducted asM.S. graduatestudent's thesis project. The 2nd objective of the research project has been completed, and the student's thesis has been published. The outcomes of this part of theresearch project were reported in refereed journals, and also theresearch data were presentedat national conferences such as Institute of Food Technologists (IFT) and American Dairy Science Association (ADSA).

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Davis, B.I., A. Siddique, A.K. Mahapatra and Y.W. Park. 2018. Survivability of Escherichia Coli in Commercial Powder Goat Milk during Four Months Storage at Two Different Temperatures. J. Adv. Dairy Res 2018, 6:200. DOI: 10.4172/2329-888X.1000200.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Park, Y.W. 2018. Recent Trend in the Dairy Industry. J. Adv. Dairy Res 2018, 6:4. DOI: 10.4172/2329-888X.1000e134.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Davis, B.I., R. Paswan, A. Siddique and Y.W. Park. 2018. Storage stability of commercial powder goat milk in relation to changes in physico-chemical properties under different temperature and time treatments. J. Dairy Sci. Vol. 101. Suppl. 2. Abstract #M6. Page 9.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Kim. C-H, M.S. Nam and Y.W. Park. 2018. Addition of Lactobacillus paracasei and Lactobacillus rhamnosus bacteria to yogurts for inhibition of yeast growth and improvement of their quality. J. Dairy Sci. Vol. 101. Suppl. 1. Abstract #M6.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Siddique, A., R. Paswan and Y.W. Park. 2018. Textural characteristics of caprine milk Cheddar cheeses supplemented with microencapsulated and regular ferrous sulfate. J. Dairy Sci. Vol. 101. Suppl. 1. Abstract #T6.

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

Outputs
Target Audience:The target audiences duringthis reporting period aredairy products (i.e., powder milk) consumers, powder milkmanufacturers, food safety inspectors, food products distributors and retailers, food microbiologists, sensory scientists, nutritionists, and dairy goat farmers in the state of Georgia, US and around the world. The specific audiences would be the health conscious consumers, who are looking for safer,healthier and better microbiological, nutritional, textural and sensory qualitiesof dehydrated milk products. Changes/Problems:The laboratory model of the spray dryer in the Food Science laboratory is out of order, therefore the non-fat powder goat milk samples werenotproduced, norcomparedwith full-fat (normal) powder goat milk products. Therefore, the commercial full-fat powder goat milk products will be used in the study instead. What opportunities for training and professional development has the project provided?The project has supportedtwo graduate students with training on the analytical procedures for evaluating microbiological, chemical, nutritional and sensory traits of powder milk products. We paidspecial focus onthe pathogen, E.coli, to determine its characteristicsduringstorage of the dried products for food safety evaluation. How have the results been disseminated to communities of interest?The results of the study have been disseminated to the scientific communities (audience) of food science and dairy science, such as food microbiology, food chemistry, dairy processing, dairy technology, dehydrated products storage and marketing, and sensory scientists, through refereed journal publications as well as national and international conferences in food science, microbiology and dairy science disciplines. What do you plan to do during the next reporting period to accomplish the goals?Examine the survivability of another dangerous pathogen, Salmonella bacteria inpowder goat milk during storage of different temperature and storage period treament regimens. Along with this main objective of the study,storage stability of the powdered goat milk products (control vs. Salmonellainoculated) are to bestudied by evaluatingwater activity, pH, fatty acids and lipid oxidation of the products.

Impacts
What was accomplished under these goals? The first objective of the proposed project was accomplished and described intheM.S. degree thesis project of a graduate student.The outcomes of the research project were published in refereed journals and throughpresentations atnational conferences such as Institute of Food Technologists (IFT) and American Dairy Science Association (ADSA).

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Gupta, B.P., A. Siddique, J.O. Jones and Y.W. Park. 2016. Cholesterol concentrations and lipolytic characteristics of commercial bovine and caprine milk yogurts during four weeks refrigerated storage. J. Adv. Dairy Res. 4:2: 1000155.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Davis, B.I., Aftab Siddique and Y. W. Park. 2017. Effects of Different Storage Time and Temperature on Physicochemical Properties and Fatty Acid Profiles of Commercial Powder Goat Milk Products. J. Adv. Dairy Res 2017, 5:193.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: G�ler, Z., A. Tekin and Y.W. Park. 2016. Comparison of Biochemical Changes in Kefirs Produced from Organic and Conventional Milk at Different Inoculation Rates of Kefir Grains. J Food Sci Nutr Therapy. 2(1): 008-014.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Son, J.Y., Y.W. Park, G. Renchinkhand, J.P. Han, J.W. Bum, S-H. Paik, J.Y. Lee And M.S. Nam. 2016. Characterizations of Kefir Grains in Fermented Whey and Their Effects on Inflammatory Cytokine Modulation in Human Mast Cell-1 (HMC-1). J. Life Sci. 26: 689-697.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Park, Y.W. 2016. Production and Composition of Milk are affected by Multivariate Factors. J. Adv. Dairy Res 4: e131. doi:10.4172/2329-888X.1000e131

Progress 05/03/16 to 09/30/16

Outputs
Target Audience:The target audiences of this research project are diary products (i.e., powder milk and cheese) consumers, dairy products manufacturers, food safety inspectors, food products distributors and retailers, milk producers, food scientists, food microbiologists, sensory scientists, nutritionists, and dairy goat farmers in the state of Georgia, US and around the world. The specific audiences would be the health conscious consumers, who are looking for healthier and better quality of microbiological, nutritional, textural and sensory characteristics of dairy goat products. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This research and experimentations have provided the three graduate students with important opportunities for hands-on-training on food microbiology and food safety research techniques toward their graduate MS degree works and professional development. How have the results been disseminated to communities of interest?The data have been reported at the 1890 Biennial Research Symposium, Atlanta, GA, as well as at the 2017 ADSA (American Dairy Science Association) national conference at Pittsburgh, PA. What do you plan to do during the next reporting period to accomplish the goals?Further expansion of this research for the first objective of this project will be conducted in order to evaluate the relationship between water activity, pH and Escherichia coli survival of the powdered caprine milk products for extended storage periods.

Impacts
What was accomplished under these goals? For the first year of the proposed projet, the first objective of the project has been initiated using commercial whole (full-fat) goat milk powder products for testing the survivability of E. coli in the powder milk products. Since the skim goat milk powder was not available, only whole goat milk powder products were examined during the first year. Low water activity (aw) is essential for extending shelf life as well as attaining microbiologically safe foods, such as in dehydrated milk products. Certain harmful microbes can enter the food chain opportunistically during processing and survive in dehydrated foods, causing serious concerns over food safety. This initial experiment of the proposed project in the first year was to investigate the survivability of Escherichia coli in powdered goat milk (PGM) at 4oC and 22oC during 0, 2 and 4 months storage. Three different lots of commercial whole goat milk powder products were purchased from a local retail outlet at Warner Robins, GA, and divided the total amount of each lot into two equal quantities to assign them to 2 treatment groups as control and E. coli inoculated groups. Ten grams of the experimental PGM samples were inoculated with 50 μL of E. coli K12, and control samples without inoculation of the pathogens were subjected to the 2 temperature and 3 storage period treatments. All experimental PGM samples were microbiologically analyzed according to the manufacturer's procedure (3M Center, St. Paul, MN). The PGM samples in duplicates were serially diluted, plated on the 3M Petrifilm EC plates, and colonies were counted after 48 h incubation at 37oC. The initial inoculation rate was at least 8 log CFU/g for each sample. Results showed that the inoculated experimental PGM contained average 5.01 log CFU/g E. coli in the initial samples. Mean E. coli counts of 4 and 22 oC at 0, 2 and 4 months storages were: 5.01, 4.16; 3.43, 1.85; and 3.77, 1.48 CFU/g, respectively, indicating that E. coli counts significantly (P<0.01) decreased during 4 months storage period. There were significant (P<0.01) differences in E. coli counts between temperatures and between storage periods for both of main factors. E. coli counts of the powder milk samples were not affected by batch effect up to 2 months, but did affect at 4 months storage. It was concluded that the survivability of E. coli in the powdered whole goat milk significantly decreased as the storage time advanced.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: B.I. Davis, J.H. Ko, K.P. Bastola, A. Siddique, J.O. Jones and Y.W. Park. 2016. Evaluation of mineral compositions in commercial Mongolian dried yogurts (Aaruul) marketed at retail stores in Mongolia. The 2016 ADSA/ASAS/CASA JAM Conference, Abst. #509. Pp 158.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Park, Y.W., J.Y. Son, G. Renchinkhand, S-H. Paik, and M.S. Nam. 2016. Effect of lactoferrin hydrolysates on cytokine expression in Raw264.7 cells. The 2016 ADSA/ASAS/CASA JAM Conference, Abst. #911. Pp 165.