ABSTRACT
Research background: Ginseng is a medicinal plant that has anti-inflammatory, antidiabetic, anticancer, antiobesity, cardioprotective, antioxidant and antimicrobial properties. However, previous reports lack information on the effects of ginseng extract on the shelf life and quality characteristics of muscle foods. Thus, it is essential to determine the effects of ginseng extract on the meat model system to gain valuable insights to improve the shelf life and quality of muscle foods. Experimental approach: After determining the in vitro antioxidant activity of ginseng extract, the antioxidant effect of ginseng extract on cooked ground beef was investigated. In vitro antioxidant activity was determined using Fe(III) reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging and total phenolic content (TPC) analyses, while lipid oxidation, chemical, microbiological and textural changes were determined during 30 days of storage. Cooking loss, proximate composition and textural features were measured after thermal processing. The pH, CIE colour parameters, thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide (LPO), total aerobic mesophilic bacteria, total coliform bacteria, yeast and mould counts were determined during refrigerated storage. Results and conclusions: The mean values for FRAP expressed as Fe(II) equivalents ((4.7±0.2) mmol/g), DPPH (IC50=(12.11±0.09) mg/mL) and TPC expressed as gallic acid equivalents ((146.0±2.4) mg/g) showed a potential antioxidant capacity of ginseng extract. The addition of ginseng extract increased the cooking loss (p<0.05), but it did not affect the proximate composition of ground beef. It also caused a decrease in pH (p<0.05). Ground beef samples containing 1 % or more ginseng extract had lower TBARS values than control (p<0.05). In addition, LPO values of ground beef with ginseng extract were lower than the control after 30 days of storage (p<0.05). Total aerobic mesophilic bacteria, total coliform bacteria, yeast and mould were not found in any of the groups, except in the control, which had 3.35 log CFU/g total aerobic mesophilic bacteria at the end of storage. Novelty and scientific contribution: The results show that ginseng extract has an important activity in controlling lipid oxidation and can be used in the meat industry to extend shelf life and microbial stability.
ABSTRACT
The objective of this study was to investigate the effects of added beta-glucan (ß-glucan) levels on the lipid oxidation, physicochemical, microbiological, textural and sensorial properties of fermented sausage produced with various amounts of beef fat during fermentation and storage periods. To determine the effects of ß-glucan, twelve sausage treatments included four controls (no ß-glucan) with or without beef fat and starter culture addition and eight ß-glucan incorporated groups produced with addition of starter culture, various levels of ß-glucan (0, 1, 2%) and different levels (0, 10, 15, 20%) of beef fat were manufactured. The results indicated that addition of ß-glucan decreased thiobarbituric acid reactive substances (TBARS) values compared to control groups which had 20% beef fat (P < 0.05). ß-glucan enhanced the growth of lactic acid bacteria during fermentation and storage periods (P < 0.05). The addition of ß-glucan caused a decrease in water activity and pH values of sausage during the fermentation and storage (P < 0.05). Color values, fatty acid composition, protein, fat, moisture and ash content were not influenced by the use of ß-glucan (P < 0.05). Higher levels of ß-glucan in sausage formulation caused an increase in the hardness values of sausage (P < 0.05).
ABSTRACT
Microbiological, physicochemical, aroma and organic acid characteristics of non-fat yoghurt incorporated with ß-glucan and probiotic Lactobacillus plantarum strains (AB6-25, AC18-82 and AK4-11) combination as adjunct culture were investigated during a 21 day storage period at 4 °C. Four treatment yoghurts contained 0.25, 0.5, 1 and 1.5 % ß-glucan. Treatments also included probiotic combination and commercial culture. Treatments were compared with three controls produced containing commercial culture, commercial culture and probiotic combination, and commercial culture, Lactobacillus acidophilus and inulin. The results indicated that ß-glucan promote the viability of lactobacilli. However, the addition of ß-glucan (except 0.25 %) resulted in enhanced syneresis (P < 0.05). In general, the use of 0.25 % ß-glucan had no significant effect on pH, fat, protein and organic acid content of non-fat yoghurt. The results obtained from this research demonstrated that the use of 0.25 % ß-glucan has no adverse effect on the characteristics of non-fat yogurt produced with probiotic combination.
ABSTRACT
BACKGROUND/AIMS: Intestinal bacteria induce endogenous signals that play a pathogenic role in hepatic insulin resistance and non-alcoholic fatty liver disease. Probiotics could modulate the gut flora and could influence the gut-liver axis. We aimed to investigate the preventive effect of two probiotic mixtures on the methionine choline-deficient diet-induced non-alcoholic steatohepatitis model in rats. METHODS: Two studies, short-term (2 weeks) and long-term (6 weeks), were carried out using 60 male Wistar rats. The 2-week study included six groups. Rats were fed with methionine choline-deficient diet or pair-fed control diet and were given a placebo or one of two probiotic mixtures (Pro-1 and Pro-2) by orogastric gavage. In the 6-week study, rats were allocated into four groups and were fed with methionine choline-deficient diet or pair-fed control diet and given a placebo or Pro-2. At the end of the 2- and 6-week periods, blood samples were obtained, the animals were sacrificed, and liver tissues were removed. Serum alanine aminotransferase activity was determined; histologic and immunohistochemical analysis was performed for steatosis, inflammation, protein expression of tumor necrosis factor-α, and apoptosis markers. RESULTS: In both studies, methionine choline-deficient diet caused an elevation of serum alanine aminotransferase activity, which was slightly reduced by Pro-1 and Pro-2. In the 2- and 6-week studies, feeding with methionine choline-deficient diet resulted in steatosis and inflammation, but not fibrosis, in all rats. In the 2-week study, in rats fed with methionine choline-deficient diet and given Pro-1, steatosis and inflammation were present in 2 of 6 rats. In rats fed with methionine choline-deficient diet and given Pro-2, steatosis was detected in 3 of 6 rats, while inflammation was present in 2 of 6 rats. In the 6-week study, in rats fed with methionine choline-deficient diet and given Pro-2, steatosis and inflammation were present in 3 of 6 rat livers. In both the 2- and 6-week studies, methionine choline-deficient diet resulted in tumor necrosis factor-α, proapoptotic Bax, caspase 3, caspase 8, and anti-apoptotic Bcl-2 expression in all rat livers. Pro-1 and Pro-2 treatment influenced protein expression involved in apoptosis and tumor necrosis factor-α in varying degrees. CONCLUSIONS: Pro-1 and Pro-2 decrease methionine choline-deficient diet-induced steatohepatitis in rats. The preventive effect of probiotics may be due, in part, to modulation of apoptosis and their anti-inflammatory activity.
