AQUEOUS GARLIC EXTRACT AND MICROBIOLOGICAL QUALITY OF REFRIGERATED POULTRY MEAT

Ability of Garlic and Ginger Oil to Reduce Salmonella in Post-Harvest Poultry

Approximately 1.35 million human salmonellosis cases are reported in the United States every year, resulting in over 26,000 hospitalizations and 400 deaths. Consumption of contaminated poultry products is one of the leading causes of human salmonellosis. Poultry meat becomes contaminated when feces from an infected bird comes into contact with the carcass during processing. Additional carcasses can then become cross-contaminated along the processing line. While chemicals such as peracetic acid are currently used to kill microbes such as Salmonella, consumers are increasingly calling for more natural alternatives. Our objective for this study was to determine the ability of the phytochemicals garlic and ginger oil to reduce Salmonella prevalence in the processing environment. In a simulated scalding tank environment, dipping contaminated chicken skin samples in a solution containing both garlic and ginger oil reduced Salmonella by up to 2 log CFU. Furthermore, the oils prevented Salmonella growth in the tank solution. The mechanism of action of garlic and ginger was evaluated using the sub-inhibitory concentration of each oil individually. While both were found to decrease autoinducer-2 (AI-2) levels, no effect was seen on expression of 10 genes involved in Salmonella virulence and survival. In total, this work demonstrates the potential of garlic and ginger to reduce Salmonella prevalence in the post-harvest environment. However, more work remains to be done to understand the mechanism of action.

Analyzing the antibacterial effects of food ingredients: model experiments with allicin and garlic extracts on biofilm formation and viability of Staphylococcus epidermidis

To demonstrate different effects of garlic extracts and their main antibiotic substance allicin, as a template for investigations on the antibacterial activity of food ingredients. Staphylococcus epidermidis ATCC 12228 and the isogenic biofilm-forming strain ATCC 35984 were used to compare the activity of allicin against planktonic bacteria and bacterial biofilms. The minimal inhibitory concentration (MIC) and the minimum biofilm inhibitory concentration (MBIC) for pure allicin were identical and reached at a concentration of 12.5 μg/mL. MBICs for standardized garlic extracts were significantly lower, with 1.56 and 0.78 μg/mL allicin for garlic water and ethanol extract, respectively. Biofilm density was impaired significantly at a concentration of 0.78 μg/mL allicin. Viability staining followed by confocal laser scanning microscopy showed, however, a 100% bactericidal effect on biofilm-embedded bacteria at a concentration of 3.13 μg/mL allicin. qRT-PCR analysis provided no convincing evidence for specific effects of allicin on biofilm-associated genes. Extracts of fresh garlic are more potent inhibitors of Staphylococcus epidermidis biofilms than pure allicin, but allicin exerts a unique bactericidal effect on biofilm-embedded bacteria. The current experimental protocol has proven to be a valid approach to characterize the antimicrobial activity of traditional food ingredients.

Microbiological contamination of dried and lyophilized garlic as a potential source of food spoilage

Garlic is valued more for its flavoring and used in a wide variety of foods. In food technology, fresh garlic is not used, but instead its processed forms, most often dried and lyophilized, are utilized. The quality and safety of the final product largely depends on their microbiological quality. This research has provided information about effect of garlic fixation methods and provided information about effect of microbiological contamination of garlic used as a spice for quality of garlic mayonnaise sauce. The authors decided to undertake studies following a report from one of the manufacturers of garlic sauces on product defects which originated in dried garlic used in the production process. Samples of garlic (n = 26) were examinated using standard cultural methods (counts of fungi, lactic acid bacteria-LAB, spore-producing Bacillus sp. and the presence of anaerobic saccharolytic and proteolytic clostridia), automated system TEMPO (total viable count, Enterobacteriaceae), immunoenzymatic method using VIDAS tests (occurrence of Salmonella sp. and Listeria monocytogenes). The number of total viable count was ranged from 3.51 to 6.85 log CFU/g. Enterobacteriaceae were detected only in one sample. Comparably low values were recorded for fungi (1.30 to 3.47 log CFU/g). The number of LAB was ranged from 2.34 to 5.49 log CFU/g. Clostridium sp. were detected in 22 samples. Salmonella sp. and Listeria monocytogenes were not detected. It was found that garlic, regardless of th preservation procedure, might be a source of contamination of garlic mayonnaise sauce especially with lactic acid bacteria and Clostridium sp. spores.

Improving functional value of meat products

In recent years, much attention has been paid to develop meat and meat products with physiological functions to promote health conditions and prevent the risk of diseases. This review focuses on strategies to improve the functional value of meat and meat products. Value improvement can be realized by adding functional compounds including conjugated linoneleic acid, vitamin E, n3 fatty acids and selenium in animal diets to improve animal production, carcass composition and fresh meat quality. In addition, functional ingredients such as vegetable proteins, dietary fibers, herbs and spices, and lactic acid bacteria can be directly incorporated into meat products during processing to improve their functional value for consumers. Functional compounds, especially peptides, can also be generated from meat and meat products during processing such as fermentation, curing and aging, and enzymatic hydrolysis. This review further discusses the current status, consumer acceptance, and market for functional foods from the global viewpoints. Future prospects for functional meat and meat products are also discussed.