Virginia Polytechnic Institute and State University |
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| Faculty:Susan Duncan, Dairy and Sensory
Evaluation
Expertise Areas: Dairy product processing and quality, sensory evaluation Phone:(540) 231-8675 Fax: (540) 231-9293 Email:duncans@vt.edu Bill Eigel, Food BiochemistryExpertise Areas: Laboratory quality control, lab analytical techniques (non-microbial) Phone: (540) 231-6877 Fax: (540) 231-9293 Email: weigel@vt.edu Joe Marcy: Food Processing Expertise Areas: Juice Processing, packaging and aseptics Phone:(540) 231-7850 Fax: (540) 231-9293 Email: jmarcy@vt.edu Merle
Pierson:
Food Microbiology Expertise
Areas: HACCP,
Dairy microbiology, Regulatory Phone: (540) 231-8641 Fax:
(540) 231-9293 Email:
piersonm@vt.edu Sean
O’Keefe:
Food Chemistry Expertise
Areas: Product
Development Phone:
(540) 231-2075 Fax:
(540) 231-9293
Susan Sumner: Food Safety Expertise Areas: Dairy microbiology, food safety, lactic acid bacteria, shelf-life and HACCP Phone: (540) 231-5280 Fax: (540) 231-9293 Email:sumners@vt.edu Dairy Staff: Walter Hartman: Dairy Plant Manager whartman@vt.edu Kim Waterman: Dairy Chemistry Kwater@vt.edu Brian Yaun: Microbiology byaun@vt.edu Phone: (540) 231-8697
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Updates at Virginia Tech
Research Highlights IMPROVED
PROPERTIES OF NATAMYCIN UPON FORMATION OF CYCLODEXTRIN INCLUSION COMPLEXES Natamycin is used to extend the shelf life of shredded cheese products. It functions as an antimycotic with very low water solubility and extremely high photosensitivity. Recent research in the Food Science and Technology Department of VA Tech attempted to find a new delivery system for natamycin that would increase its aqueous solubility. Methods were also examined for increasing natamycin’s chemical stability in order to prolong its antifungal effect on the surface of the shredded cheese. Molecular inclusion complexes of natamycin were formed with b-, hydroxypropyl b-, and γ-cyclodextrins (CDs). These complexes allowed large increases in aqueous solubility without the use of organic co-solvents or surfactants. The water solubility of natamycin was increased 16-fold, 73-fold, and 152-fold with b-CD, g-CD, and hydroxypropyl b-CD, respectively. The natamycin:CD inclusion complexes resulted in nearly equivalent in vitro antifungal activity as natamycin in its free state. Nuclear magnetic resonance (NMR) was utilized to prove the formation of true inclusion complexes. 1H NMR shift titrations of N-(3’-N-dimethylaminosuccimido) natamycin with b- and γ-CDs enabled determination of the stoichiometry of both complexes as 1:1. Aqueous solutions of natamycin (20 mg/L) were found by quantitative HPLC to be completely degraded after 24 hours of exposure to 1000 lux fluorescent lighting at 4 °C. After 14 days of storage in darkness at 4 °C, 92.2% of natamycin remained in active form. Aqueous solutions of natamycin:b-CD complex and natamycin:γ-CD complex were significantly more stable (p < 0.05) than natamycin in its free state when stored in darkness at 4 °C. Clear poly(ethylene terephthalate) packaging with an ultraviolet light absorber allowed 85.0% natamycin to remain after 14 days of storage under 100 0 lux fluorescent lighting at 4 °C. Such dramatic increases in water solubility and light stability will enable natamycin to function as a more effective antimycotic in the food industry. HOT
TOPICS AND DAIRY ISSUES
Dean
Gets Aseptic Approval Dean Foods’ Morningstar division has won FDA approval to extend the
shelf life of its Hershey’s flavored Milks and Shakes and Folgers Jakada to
180 days and to store and ship the product at ambient temperature.
The company produces the single-serve beverages on a custom-designed
filling line from Stork Food and Dairy Systems in Mt. Crawford, VA.
Dean officials have indicated that there are plans to install a similar
line at a west coast plant. Functional Food Claims Rules Relaxed Washington – FDA plans to allow companies to make certain health claims
for foods even though the stated health benefits may still be the subject of
scientific debate. At the same time, the agency said it intends to beef up
enforcement against misleading health claims by the dietary supplements
industry. FDA Commissioner Mark McClellan said both moves are intended to give
consumers more information about foods and dietary supplements and provide
consistency in how the agency treats health claims for both. Under the new FDA
guidance, companies will be able to submit qualified health claims for
conventional foods based on “the weight of scientific evidence,” an easing
of a previous requirement that there be a consensus backed by “the totality of
publicly available scientific evidence.”
FDA officials said the change would allow a company, for example, to
submit a health claim saying foods containing omega-3 fatty acids, found in some
fish products, may reduce the risk of coronary disease. Salmonella
Outbreak in Ohio Young’s Jersey Dairy, a Dayton specialty dairy that has a grandfather
clause to sell raw milk products, has been linked to a December Salmonella
outbreak that affected more than 40 people.
The company has since stopped selling unpasteurized milk and stopped
using it in milk shakes. |
