Progress 03/01/01 to 02/28/07
Outputs
Our research has investigated the impact of source (herd type), processing (method of dehydration) and thermization (controlled heat treatment) on the functionality of whey powders (as reported earlier). We have also determined the influence of the above mentioned variables on the textural and sensory qualities of selected dairy foods in which the whey powders were used. In order to better understand the molecular basis of whey protein functionality, thermal association tendency (AT) of various whey proteins was also investigated. This was done since AT is known to impact numerous food functional attributes of proteins. The AT of gelling (beta-lactoglobulin AB (B-LA), alpha-lactalbumins (A-LA), bovine serum albumin (BSA)) and non-gelling (alphas1-casein (A-CN), beta-casein (B-CN) and kappa-casein (K-CN)) whey protein dispersions (1%, w/v) were studied by Quasielastic Light Scattering in the pH range of 3.5 to 9 at temperatures varying from 5 to 80C. The mean aggregate
diameter profiles reflected conformational transitions reported in the literature and these resulted in markedly increased AT. Ratio of the contribution of pH and heat to AT of the gelling proteins, B-LG and BSA, were 1 to 2.2 and 4, respectively, indicating strong thermal susceptibility. Among the non-gelling proteins, A-LA and K-CN were similarly influenced by pH and heat with the ratio being 1:1.2 and 1.1:1, respectively. B-CN, was an exception in that, (i) it showed no aggregate enlargement with heat, and (ii) its susceptibility to pH regulated AT was 20 fold greater than it was to heat. Conversely, the ratio of A-CN was 5 fold greater in favor of thermally induced AT. Inability of A-CN to form self-supporting gels in spite of strong thermal susceptibility was attributed to conceivable architecture of its thermally associated clusters. Close proximity, that allows formation of tenacious disulfide bond and salt-bridges, and others interactions like van der Waals, ionic contacts,
may not be possible due to charge repulsion and steric hindrance of numerous phosphate groups on the A-CN surface. The number of serile phosphates in A-CN varies in the five known variants (A1 to 5) from 8 in αs1-casein B-8p to 11 in αs2-casein A-11P. In contrast, the heat treated gelling proteins, which are comparatively compact due to retained secondary structure, have exposed core hydrophobicities that glue the aggregate in sufficiently close proximity, in order to decrease hydrocarbon-aqueous interface, as the surrounding entropy increases due to heat induced breakdown of water structure.
Impacts
Our study has provided insight into how processing and source of whey influence key desirable attributes of whey powders and also how controlled heat-treatment can be used to produce heat-stable whey powders that may be used to produce retort-stable products. Our related basic studies have shed light on the molecular basis of difference in the gelling properties of whey proteins.
Publications
- Kucukoner, E.; Haque, Z.Z. 2006. Physicochemical properties of low-fat and full-fat Cheddar cheese. Int. J. Dairy Technol. 59(3):166-170.
- Haque, Z.Z., Suh, K., Ansari, R. 2006. Thermal association tendency of gelling and non-gelling proteins. Abstract 034-6. Book of Abstracts of 2006 IFT Annual Meeting. July 24-28, Orlando, FL.
- Shon, J., Haque, Z.Z. 2006. Efficacy of sour whey in natural antioxidative edible coatings of cut vegetables and fruit. Abstract 110-08. Book of Abstracts of 2006 IFT Annual Meeting. July 24-28, Orlando, FL.
- Shon, J., Haque, Z.Z. 2006. How thermization significantly enhances the thermostability of sour and sweet whey. Abstract 054D-15. Book of Abstracts of 2006 IFT Annual Meeting. July 24-28, Orlando, FL.
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Progress 01/01/05 to 12/31/05
Outputs
Sour and sweet whey are rich in enzymes originating mainly from starter cultures activity. These cause protein breakdown that in turn results in inconsistent functionality. An enzyme inactivating heat treatment step, or thermization, well in excess of normal pasteurization conditions, is imperative to assure quality. Since whey proteins are thermo-labile, it is relevant to evaluate the affect of a thermization step on key functional attributes of whey powders. As part of our project related to the study of the functionality of whey, the objective of this study was to evaluate the effect of thermization at 80C for 30 min of sour whey from cottage cheese manufacture, and sweet wheys from Edam and Cheddar cheese manufacture on key functional attributes; solubility, dispersion opacity or turbidity, oil-holding-capacity, thermostability, emulsifying and foaming properties. Pasteurized skimmed milk was used for Cottage, Edam and Cheddar cheese manufacture and after the
cheese curd was removed, whey samples were divided into two equal portions. One portion was immediately flash frozen in liquid nitrogen and lyophilized to obtain native sour, Edam and Cheddar whey powders. The other portion was batch heated at 80C (+ or - 0.1) for 30 min prior to flash freezing and lyophilization to obtain thermized sour, Edam and Cheddar whey powders. Thermization detrimentally impacted solubility, emulsifying and foaming properties and significantly enhanced thermostability of all powders. The increase was the highest for Edam whey and best demonstrated at acidic pH values of 3.0 and 4.5, where thermostability increased by 57 and 53, 181 and 167, and 31 and 48%, for cottage, Edam, and Cheddar, respectively.
Impacts
Data obtained indicate that thermization has significant functional advantage in that it deactivates bacteria and enzymes, that are major causes for variability of functionality, and also markedly improves a key attribute that will allow manufacture of pasteurization and retort stable whey powders for used in high and low acid beverages that need to be heat treated.
Publications
- Aryana, K. J. and Haque, Z.U. 2005. Texture and microflora of Vallagret cheese during maturation. Int. J. Dairy Tech. 58(1):47-51.
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Progress 01/01/04 to 12/30/04
Outputs
Antioxidative properties of acid whey (cottage cheese)(AW) were compared with those of SW (Edam and Cheddar) and other natural and artificial antioxidants. Thiobarbituric acid-reactive substances (TBARS) and peroxide value (PV) formation in iron-catalyzed peanut oil emulsion were significantly (p<0.05) reduced by AW and the SWs. Edible AW films significantly reduced storage (4C) induced TBARS and PV in beef steaks and decreased protein oxidation based on stability of carbonyl and sulfhydryl groups. Data indicate that AW was comparable, if not better, than the SW and antioxidants tested in terms of the antioxidative properties studied.
Impacts
Our work shows that AW, which is presently considered to be a waste product, could conceivably be effectively used as a healthy and natural antioxidant in food systems. This would potentially increase utilization of this undesirable by-product of cottage cheese manufacture and thereby decrease an expensive disposal problem.
Publications
- Shon, J.H. and Haque, Z.Z. 2004. Effect of whey protein edible coating on beef steak with or without carboxymethyl cellulose. Abstract #79-7. Technical Book of Abstracts, 64th Annual Meeting of the Institute of Food Technologists, July 12-16, Las Vegas, NV.
- Shon, Jin-Han. 2004. Antioxidative and Physico-chemical Properties of Acid Whey. Ph.D. Dissertation, Mississippi State University, MS, (Z.Z. Haque, Major Professor and Research Director).
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Progress 01/01/03 to 12/31/03
Outputs
Cheddar whey, from either a Jersey (J) or a mixed herd (M), was used to observe the effect of source (WSr) on the composition and functionality of whey-based ingredients and their effects, per se, on dairy food quality. Four commonly used whey dehydration processes (WPr) were carried out at a pilot plant level to obtain different whey protein concentrates (WPC). Though both WSr and WPr influenced WPC functionality, WPr appeared to have a dominate effect in terms of solubility, thermostability, and emulsifying properties. Data also indicated that both WSr and WPr impacted desired attributes of dairy product quality differently.
Impacts
The present study provides an understanding of how dehydration methods used during whey ingredient production impact powder quality. The study further illustrates the impact of the different powders on quality attributes of dairy products. The industry has also been concerned about the functional inconsistency of whey-based ingredients. Our studies will allow U.S. whey-based ingredient manufacturers to produce high quality whey ingredients that will compete better with ingredients manufactured in Europe, Australia, and New Zealand.
Publications
- Ji, T. and Haque, Z.U. 2003. Cheddar whey processing and source: 1. Effect on composition and functional properties of whey protein concentrates. Internat'l. J. Food Sci. Technol. 38:453-461.
- Haque, Z.U. and Ji, T. 2003. Cheddar whey processing and source: 2. Effect on nonfat ice cream and yogurt. Internat'l. J. Food Sci. Technol. 38:463-473.
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Progress 01/01/02 to 12/31/02
Outputs
Beta-lactoglobulin AB contributes to the typical physicochemical behavior of whey protein concentrates (WPC). We concluded a detailed study looking at the mechanism of thermal gelation of this protein. Herd type (source) and method of thermal dehydration markedly affected functionality of WPC and their impact on quality of dairy products. Electron microscopic studies showed the formation of lipophilic surface-active complexes by vacuum evaporation, a technique commonly used by the industry. Our data also indicated significant microstructural and functional effects of trace minerals on serum albumin, a hyper-functional whey component.
Impacts
Our studies, and related publications and presentations, provide insight into the molecular and microstructural basis for the relationship between processing variables and physicochemical functionality of whey protein concentrates. This knowledge is basic, and yet pragmatic in that it provides understanding that may allow improved quality control of an under-utilized resource that, for too long, has been considered a by-product rather than an excellent source of functional ingredients. Today, the economics of dairy manufacturing is such that the US cheese manufacturer cannot survive and compete without further processing and marketing the whey as a source of hyper-functional food ingredients.
Publications
- Haque, Z.U. and Sharma, M. 2002. Influence of cation sequestering and pH on quiescent thermal association of B-lactoglobulin AB from fresh Cheddar whey: An insight into gelation mechanism. Food Sci. Technol. Res. 8(4):311-316.
- Aryana, K.J. and Haque, Z.U. 2002. Microstructure and some functional properties of spray-dried Cheddar whey concentrate by ultrafiltration or combination of ultrafiltration and vacuum evaporation. Food Sci. Technol. Res. 8:17-20.
- Haque, Z.U. and Aryana, K.J. 2002. Effect of copper, iron, zinc and magnesium ions on bovine serum albumin gelation. Food Sci. Technol. Res. 8:1-3.
- Aryana, K.J., Haque, Z.U. and Gerard, P.D. 2002. Influence of whey concentrates on the functionality of egg white and bovine serum albumin. Int. J. Food Sci. Technol. 37:643-652.
- Haque, Z.U. and Aryana, K.J. 2002. Effect of sweeteners on the microstructure of yogurt. Food Sci. Technol. Res. 8:21-23.
- Haque, Z.U., Monsoor, M.A. and Chowdhury, Z. 2002. Effect of heating on apparent digestibility of some infant formulations and cereal-legume blends available in Bangladesh. Pakistan J. Nutr. 1:69-72.
- Haque, Z.U. and Aryana, K.J. 2002. Volatiles in lowfat Cheddar cheese containing commercial fat replacers. Food Sci. Technol. Res. 8(2):188-190.
- Khosravi, P. 2002. Influence of calcium fortification and storage time on orange juice quality. MS Thesis, Food Sci. Technol., MSU.
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Progress 01/01/01 to 12/31/01
Outputs
In order to observe the effect of process parameters on functionality of whey powders in a novel food application, a commercial preparation, whey protein concentrate produced by ultrafiltration and spray-drying (WPC34), and a diafiltered (low mineral) WPC were used to make edible films. Sorbitol was used as the plastisizer and antioxidants (BHA, BHT, tocopherol and spice oleoresins) are being used to assess oxygen protective property as impacted by whey process parameters. The total radical-trapping potential (TRAP) of the whey films are being determined using Luminol-induced Chemiluminescence as a tool. Different varieties of soybean are also being obtained to assess film forming ability and to assess residual antioxidative, mechanical, and moisture protective activity. High-performance liquid chromatographic techniques are being standardized for the above purpose.
Impacts
Protein-based ingredients, like whey and soy protein concentrates, are known to be inconsistent in terms of functionality in food systems. This variability is generally blamed on process parameters, especially those that entail heat and/or shear. The present work looks carefully at these manufacturing steps and at how they correlate to model functionalities and desired attributes in foods.
Publications
- Aryana, K.J and Haque, Z.U. 2001. Effect of commercial fat replacers on the microstructure of low-fat Cheddar cheese. Int. J. Food Sci. Technol. 36:169-177.
- Aryana, K.J. and Haque, Z.U. 2001. Microstructure of Jarlesburg-type and Edam cheeses as influenced by maturation. J. Food Quality. 24:337-350.
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