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Biogenic amines produced by Enterobacteriaceae isolated from meat products

Biogenic amines in ground meat and processed meat products are one of the indicators to determine the poor quality raw material. Major histamine forming bacterium was Escherichia coli (strain EC04 with 65.88 mg/100 ml in Brain Heart Infusion medium), followed by the microorganisms Morganella morganii (strain MM4 with 8.40 mg/100 ml and strain MM7 with 8.28 mg/100 ml) and Proteus mirabilis (strain PM02 with 8.76 mg/100 ml), respectively. The highest putrescine production level was found in Citrobacter freundii and Enterobacter spp. strains, followed by Serratia grimesii, Proteus alcalifaciens, E. coli, Escherichia fergusonii, Morganella morganii, Proteus mirabilis, Proteus penneri and Hafnia alvei, respectively. The most important cadaverine producer was E. coli EC03 with a production level of 45.48 mg/100 ml, and of the strains Escherichia vulnaris EV01, Escherichia fergusonii EF06 produced 37.92 mg/100ml and 35.40 mg/100 ml, respectively. On the basis of our results, it can be concluded that the major biogenic amines produced by Enterobacteriaceae are putrescine, cadaverine, tyramine and histamine, both in culture medium and meat products.

Oleuropein using as an Additive for Feed and Products used for Humans

Olive tree has been accepted as a symbol of holiness, abundance, wisdom and health, for centuries. Although its fruit is mainly used as a food after processing for table olive and olive oil, it is used for preparing medical products, cosmetic and animal feed. Olive trees have been cultivated for thousands of years, but the immune and circulatory benefits of olive leaf have only recently become fully realized. Olive leaf was first used medicinally in Ancient Egypt and was a symbol of heavenly power. There are many in vivo and in vitro researhes has been done on the effects of Oleuropein, one of the most important phenolic compound extracted from olive leaves, on health. The effects of the olive tree, accepted as an elixir of health and especially its product Oleuropein on human health and as an additive for animal feeds.

Role of milk protein–based products in some quality attributes of goat milk yogurt

Goat milk yogurts were manufactured with the fortification of 2% (wt/vol) skim goat milk powder (SGMP), sodium caseinate (NaCn), whey protein concentrate (WPC), whey protein isolate (WPI), or yogurt texture improver (YTI). Yogurts were characterized based on compositional, microbiological, and textural properties; volatile flavor components (with gas chromatography); and sensory analyses during storage (21d at 5 °C). Compared with goat milk yogurt made by using SGMP, the other goat milk yogurt variants had higher protein content and lower acidity values. Goat milk yogurts with NaCn and WPC, in particular, had better physical characteristics. Using WPI caused the hardest structure in yogurt, leading to higher syneresis values. Acetaldehyde and ethanol formation increased with the incorporation of WPI, WPC, or YTI to yogurt milk. The tyrosine value especially was higher in the samples with NaCn and YTI than in the samples with WPC and WPI. Counts of Streptococcus thermophilus were higher than the counts of Lactobacillus delbrueckii ssp. bulgaricus, possibly due to a stimulatory effect of milk protein-based ingredients other than SGMP on the growth of S. thermophilus. Yogurt with NaCn was the best accepted among the yogurts. For the parameters used, milk protein-based products such as NaCn or WPC have promising features as suitable ingredients for goat milk yogurt manufacture.