Progress 10/01/08 to 09/30/12
Outputs
OUTPUTS: The purpose of this project is the use of polymerized whey protein, with additional nanoclays for reinforcement, to produce flexible coatings. Nanoclays with varying degrees of hydrophobic behavior are added to a whey protein solution and a combination of clay, polymer, plasticizer and preservative in varying ratios has been investigated. The type of mixing procedure, processing of polymers and coating procedure were also investigated. We have developed a coating material containing polymerized whey protein which has good flexibility and is waterproof for several days. This type of material would be suitable for disposable food containers. Laboratory trials including coating procedures, optimum depth of layers, flexibility and appearance (color, gloss, haze index and transparency) are all required and water/oil resistance, shelf life, microbial resistance and oxygen permeability are of major importance. Adhesion testing, after the coating process, quantifies the strength of the bond between substrate and coating while quantity of coating material impregnated inside paper (and therefore not part of the continuous layer on the surface of the paper) is also of importance. Procedures for each of these types of trials have been developed (based principally on ASTM) and modified for the specific materials we are investigating. Formulation of a coating product that will bond to a metal surface, and be non-reactive on its food contact surface, is in progress. A variety of manufacturing procedures and raw materials are being assessed. Additional organic waterproofing materials such as waxes are being investigated. Use of a commercial wax based solution did not have a sufficient waterproofing effect so beeswax and two long chain fats are under investigation. Beeswax is difficult to manipulate due to its melting point so variation in heating procedures and point of addition are also being investigated. While this product is strong and flexible when it can be manipulated into a film it currently sets unreliably and too rapidly. The use of setting-time extenders is the next stage of experimental work. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
AFM results appeared to show films to have well dispersed clay particles and otherwise a smooth topography. The analysis was compared to a control containing no nanoclay which had a much less smooth topography, this roughness may be caused by electrostatic forces on the whey proteins at the film surface. However AFM is limited in its ability to determine intercalation rates and TEM and SEM would add further information to the clay dispersion in the product. Packagings help provide a gas, oil and moisture barrier between foods and the environment. This is extremely important for the maintenance of the specific type of food at its optimum quality. The majority of packaging which provides good quality barriers is made from synthetic plastics and these have a substantial impact on the environment when disposed of as waste. They also may have leaching effects, damaging to health. Nanoclays such as smectite clays are relatively inexpensive, widely available and have low environmental impact. This project addresses the issue of development of commercially-viable, environmentally-safe alternatives to packaging materials currently on the market. The consumers will benefit from the project outcome as there is a decreased risk of chemical intake from this type of product. Further, as with other non-petrochemical based packaging, there is potential reduction of impact to the environment from the disposal of plastics and a potential to reduce the amounts of petrochemicals used for these products.
Publications
- No publications reported this period
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: Lactic acid bacteria (LAB) are the most common type of microbes used as probiotics. They have been used in the food industry for many years. However, these beneficial organisms often encounter many harsh conditions such as acid, alkali, heat and salt stresses during food processing. This project was to develop a new practical technology using polymerized whey protein based microcapsulation to improve survivability of probiotic lactobacilli in food systems. The microencapsulated cultures of Lactobacillus acidophilus NCFM by polymerized whey proteins (PWP) and/or sodium alginate (SA), and free culture were subject to artificial digestions to determine the survival rate. The entrapment yield for the PWP method was significantly higher than the control samples. Viable counts of the culture after digestion processes were higher compared with other two groups. This microencapsulation is an effective way in protection of L. acidophilus in yogurt. PARTICIPANTS: Zheng, Z. Graduate student Zhang, T.H. Postdoctoral visiting scholar TARGET AUDIENCES: Lactic acid bacteria (LAB) are the most common type of microbes used as probiotics. They have been used in the food industry for many years. However, these beneficial organisms often encounter many harsh conditions such as acid, alkali, heat and salt stresses during food processing. This project was to develop a new practical technology using polymerized whey protein based microcapsulation to improve survivability of probiotic lactobacilli in food systems. The microencapsulated cultures of Lactobacillus acidophilus NCFM by polymerized whey proteins (PWP) and/or sodium alginate (SA), and free culture were subject to artificial digestions to determine the survival rate. The entrapment yield for the PWP method was significantly higher than the control samples. Viable counts of the culture after digestion processes were higher compared with other two groups. This microencapsulation is an effective way in protection of L. acidophilus in yogurt. The results showed that this whey protein based microencapsulation technology is an effective and economical method compared with polysacchride based method to improve the quality of fermented dairy foods. Because of whey is a by product of cheese making, this new technology may be further to benefit the well being of consumers, the dairy industry, and protect the environment of the state of Vermont and beyond. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The results showed that this whey protein based microencapsulation technology is an effective and economical method compared with polysacchride based method to improve the quality of fermented dairy foods. Because of whey is a by product of cheese making, this new technology may be further to benefit the well being of consumers, the dairy industry, and protect the environment of the state of Vermont and beyond.
Publications
- Zheng Z, Jiang Y, Chen X, Wang J, Cheng J, Zhang H and Guo M. 2011. Microencapsulation of probiotic cultures using polymerized whey proteins as wall material. J. Dairy Science. 94 (E-Suppl. 1):34.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Oats and oat products are functional in terms of health benefits for the consumers. However, the availability of fermented oats products is very limited in the US market. A functional oats based symbiotic yogurt was formulated developed. PARTICIPANTS: Helen Walsh, graduate student, UVM Jane Ross, faculty, UVM TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The new oats based yogurt is low in fat, hight in soluble fiber and containing both prebiotics and probiotics. Sensory evaluation results indicated this new product is well accepted by the taste panel. The survivability of probiotics was up to 8 weeks for two of the three cultures. The results showed that polymerized whey protein can be used as a gelation agent for making oats based yogurt.
Publications
- Walsh, H., J. Ross, and M.R. Guo. 2008. Physiochemical characteristics, probiotic viability and microstructure of an oat based yogurt like product. Book of Abstracts IFT 2008 Annual Meeting, p140.
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