Annel K. Greene

Review: Functional Properties of Kefir

Kefir is a unique cultured dairy product due to combined lactic acid and alcoholic fermentation of lactose in milk. Kefir is produced by microbial activity of “kefir grains” which have a relatively stable and specific balance of lactic acid bacteria and yeast. Due to the claimed health benefits of kefir which include reduction of lactose intolerance symptoms, stimulation of the immune system, lowering cholesterol, and antimutagenic and anticarcinogenic properties, kefir has become an important functional dairy food and consequently, research on kefir has increased in the past decade. In the following review, recent studies on the functional properties of kefir are reviewed.

Functional Properties of Vinegar

A variety of natural vinegar products are found in civilizations around the world. A review of research on these fermented products indicates numerous reports of health benefits derived by consumption of vinegar components. Therapeutic effects of vinegar arising from consuming the inherent bioactive components including acetic acid, gallic acid, catechin, ephicatechin, chlorogenic acid, caffeic acid, p-coumaric acid, and ferulic acid cause antioxidative, antidiabetic, antimicrobial, antitumor, antiobesity, antihypertensive, and cholesterol-lowering responses. The aims of this article are to discuss vinegar history, production, varieties, acetic acid bacteria, and functional properties of vinegars.

Effect of ozonated water sanitization on gasket materials used in fluid food processing

Abstract Standard-molded, one piece O-ring food processing plant gaskets (1.5 in or 36.1 mm diameter) made of seven different substances (Buna N, white Buna N, EPDM (ethylene propylene diene monomer), polyethylene, silicone rubber, PTFE (polytetrafluoroethylene or Teflon) and steam-resistant Viton) were treated with chlorine sanitizer or ozonated water. After treatment, only very slight differences were noted visually between control and treated gaskets. Measurements indicated that ozone treatment affected the tensile strength of EPDM and Viton, but not significantly more than chlorine treatment. The tensile strengths of other gasket materials were not significantly affected by ozone treatment. The elasticity of ozone-treated PTFE gaskets was significantly different from chlorine-treated PTFE gaskets. Other gasket materials were not significantly affected by ozone treatment.

Bacterial Diversity in Dried Colostrum and Whey Sold as Nutraceutical Products

UNLABELLED The microbial communities were analyzed from commercially available dried dairy nutraceutical products, including 4 brands of dried colostrum, 2 brands of dried whey, and 1 brand of nonfat dry milk. A culture-dependent 16S rRNA sequencing approach was utilized to elucidate the identity of individual isolates recovered from each dried dairy product. Approximately 69% of all bacterial isolates were members the genus of Bacillus, while approximately 14% of all bacterial isolates were identified as members of the genus Pseudomonas. Members of the Kocuria, Microbacterium, and Enterococcus genera were identified as well. PRACTICAL APPLICATION This project investigated the microbial populations inherent in dried commercially available nutraceutical products. Bovine colostrum has been reported to have protective activity against certain viral and bacterial pathogens. This project was designed to identify the bacterial populations within dried dairy nutraceutical products to determine if any species were common to all products and which may impact the reported nutraceutical properties.

Sanitary Evaluation of Target Flowmeter Used in a Dairy Processing Plant

A target flowmeter, used to measure raw milk flow, was examined for sanitary conditions in a university dairy plant 10 times over a period of eight weeks. The flowmeter connection was swabbed at four different locations along the dairy plant connection at four different times during the work day: i) after chlorine sanitization, before product; ii) after product, before cleaning in place (CIP); iii) after CIP, before acid sanitization; and iv) after acid sanitization, at end of day. Samples were plated in duplicate on standard plate count agar and on violet red bile agar. After routine CIP cleaning and sanitization procedures, bacterial counts were low. Additionally, no finished product contamination problems were detected over the 7 months of flowmeter use as shown by routine quality control tests on pasteurized milk which had flowed past the in-line meter as raw milk. These results indicate that normal cleaning and sanitization procedures were adequate for the in-line flowmeter.

Target flowmeter used in a dairy processing plant

A target flowmeter was installed in a commercial dairy plant and examined for accuracy over a period of 4 months. The flowmeter was installed after the cooling section of a HTST pasteurizer operating at approximately 378·5 liters/min. Product flow was monitored by the meter and compared to the total amount of product packaged. Seven different products were monitored: skim milk, milk with 12%, 1% or 2% milk fat, Jersey milk with 2% fat, Jersey whole milk, and a 1% fat A/B NutrishTM product. Comparison of the volume metered versus the volume packaged indicated no significant difference for any product at P < 0·05. Results of this study, which also included installation in an intermittent flow line, indicated that the target flowmeter can accurately assess amount of product in applications in which flow is continuous.

Testing a Nonpathogenic Surrogate Microorganism for Validating Desiccation-Adapted Salmonella Inactivation in Physically Heat-Treated Broiler Litter

Thermal resistance of desiccation-adapted Salmonella Senftenberg 775W was compared with that of Enterococcus faecium NRRL B-2354 in aged broiler litter. Aged broiler litter with 20, 30, and 40% moisture contents was inoculated separately with desiccation-adapted Salmonella Senftenberg 775W and E. faecium NRRL B-2354 at ca. 5 to 6 log CFU/g and then heat treated at 75, 85, and 150°C. At all tested temperatures, desiccation-adapted E. faecium NRRL B-2354 was more heat resistant than desiccation-adapted Salmonella Senftenberg 775W ( P < 0.05). During the treatments at 75 and 85°C, E. faecium NRRL B-2354 in aged broiler litter with all moisture contents was reduced by 2.89 to 4.12 log and was above the detection limit of direct plating (1.30 log CFU/g), whereas Salmonella Senftenberg 775W could not be detected by enrichment (>5-log reduction) during holding time at these temperatures. At 150°C, E. faecium NRRL B-2354 in aged broiler litter with 20 and 30% moisture contents was still detectable by enrichment after heat exposure for up to 15 min, whereas Salmonella Senftenberg 775W in aged broiler litter with all moisture contents could not be detected throughout the entire treatment. Our results revealed that E. faecium NRRL B-2354 can be used as a surrogate for Salmonella to validate the thermal processing of poultry litter by providing a sufficient safety margin. This study provides a practical tool for poultry litter processors to evaluate the effectiveness of their thermal processing.