Vol 6 No 4 (2020): Autumn

Review Article(s)

  • XML | PDF | downloads: 228 | views: 220 | pages: 168-182
    Probiotics and Lactic Acid Bacteria play important roles such as the production of antimicrobial compounds and other metabolites. So they have positive effects on human health. When reactive oxygen species generated in excess or cellular defenses are deficient, biomolecules can be damaged by the oxidative stress process. Various studies have shown that the best way to deal with the damages of oxidative reactions to protect the human body is to prevent them, which is possible by using compounds called antioxidants. Due to the damages of synthetic antioxidants, the usage of them has been discussed. Nowadays natural antioxidants from bio-resources have received a great deal of attention. Among probiotics beneficial effects, the protection against oxidative stress has been reported by many researchers. Based on the hypothesis of some scientists, probiotic bacteria exert their protective effects against oxidative stress by restoring gut microbiota. This type of microorganisms indicated their antioxidant activity by producing and increasing antioxidant enzymes, production of secondary metabolites, small hydrolyzed peptides in food, resistance to the presence of hydrogen peroxide, and production of intracellular and extracellular compounds such as Exopolysaccharides. Also, they have shown their positive effect on in vivo models. In conclusion, the results of studies indicated that lactic acid bacteria and probiotics are a major source of natural antioxidants, therefore, they have important research value and market development potential. Also, it should be noted that the mechanism of antioxidant activity of this group of microorganisms has not been fully investigated, this requires further research.

Original Article(s)

  • XML | PDF | downloads: 269 | views: 342 | pages: 183-197
    This study was conducted to determine the mean concentration of heavy metals such as lead (Pb), copper (Cu), zinc (Zn), chromium (Cr), manganese (Mn), nickel (Ni), selenium (Se), magnesium (Mg), and iron (Fe) in canned/packed fruits juices, collected from various stores in Lahore in a period of three months. These juices were categorized into four groups; local packed and canned and also imported packed and canned products. Every group consisted of ten samples. By using the di-acid digestion method, the collected samples were digested and analyzed under Atomic Absorption Spectrophotometer (AAS). The results indicated that the mean values of 7 out of 9 tested heavy metals including Pb, Mg, Ni, Fe, Cr, Se and Mn were above permissible limits (set by WHO) in all four understudy groups. Therefore, it was concluded that commercially available fruit juices are not all safe according to their heavy metals content for human consumption despite their nutritive values.
  • XML | PDF | downloads: 300 | views: 277 | pages: 198-204
    Histamine is the most common biogenic amine and is responsible for Scombroid fish poisoning. The presence of histamine at high concentrations in foodstuff indicates a public health issue Therefore, to the assurance of safety and quality, the monitoring of histamine concentration in fish and fishery products is urgent. To this aim, histamine content in 30 samples of canned tuna was measured by the UV-Vis spectrophotometry method. Linear regression was gained (R2 = 0.9905). The range of histamine levels was calculated between 85.04-125.08 mg kg-1 with an overall mean of 98.104 ± 5.18 mg kg-1. 40% of the samples were contained more than 100 mg kg-1, the allowable limit declared by Iranian National Standard (INS). However, The histamine amount of all samples were below the limit set by Codex Alimentarius (200 mg kg-1). There was no significant difference between the mean values of histamine in various brands of canned tuna. This spectrophotometric method used in this study can be introduced as a simple, applicable method for rapid monitoring of fish products, which is based on histamine reaction with copper and Alizarin Red S.
  • XML | PDF | downloads: 73 | views: 88 | pages: 205-220
    Consumer demand for both natural food colorants and non-thermal methods of preservation has increased overwhelmingly during the last few decades. Preventing loss of appeal and color through non-thermal methods without compromising on quality will provide an alternative to conventional thermal methods. In the present study, irradiation of plum peel anthocyanins after extraction and purification was done in a range of 0.1 - 1.0 kGy. Results revealed that degradation was significantly (p ≤ 0.05) dependent on both time and dose of irradiation. The percentage degradation observed in the first 3 h of treatment was 9.0 – 21.0±1.2%. The maximum anthocyanin degradation recorded during 8 h of irradiation was 45.3%. Anthocyanin degradation was apparently less at 0.1 – 0.5 kGy compared to 0.6 – 1.0 kGy. The retention of anthocyanins was up to the extent of 88.8 – 62.3% in samples irradiated at 0.1 – 0.5 kGy. Comparison of the individual anthocyanin indicated that diglucoside anthocyanins were stable towards irradiation than monoglucoside anthocyanins. For monoglucoside anthocyanins, a 50% decrease was observed as the irradiation treatment exceeded 0.6 kGy. A close comparison of the data revealed that at irradiation dose of 1.0 kGy, the decrease in L* and a* values was almost four and three times higher than that observed in samples irradiated at 0.5 kGy and below; while an increase in b* value was almost double. In spite of marginal degradation in color, low dose irradiation (up to 0.5 kGy) significantly (p ≤ 0.05) increased the antioxidant activity of the plum peel anthocyanins.
  • XML | PDF | downloads: 93 | views: 101 | pages: 221-234
    Different strains of lactic acid bacteria are the most common microbes known as probiotics. Two major kinds of probiotic bacteria are members of the genera Lactobacillus and Bifidobacterium, that are generally associated with the genus Lactobacillus which plays a vital role in the body health, as well as the ability to produce antimicrobials and vitamins in the gastrointestinal tract. The purpose of the study was the isolation of probiotics in traditional cheeses that are produced from the natural flora of the newborn mammalian digestive tract. Bacteria from lamb and kid abomasum are added to milk. The curd is slaughtered from the abomasum of a lamb or kid that is suckling and has now no longer began out to devour forage, after which its belly is dried, that is referred to as curd. In this study, sixteen samples of cheeses local to Markazi province of Iran have been prepared. The isolated bacteria have been examined for morphological, biochemical, probiotic properties, and molecular identity. Out of sixteen traditional cheese samples, five kinds of Lactobacillus have been diagnosed through PCR. L. casei strain J026 strain was identified in the traditional cheese samples as the most genera. Using probiotic starters from local sources is a beneficial strategy for producing traditional cheese, which the native strains are more compatible with the humans’ intestinal flora and therefore may also higher play their probiotic’s characteristic. 
  • XML | PDF | downloads: 162 | views: 281 | pages: 235-242
    In livestock, biosecurity, animal welfare and meat quality have a synergetic effect on the final product. To meet minimal safety and humane production, it is necessary to consider biosecurity risks and procedures to mitigate animal welfare problems. Following guidelines to achieve it, the meat quality improves consequently. Here we tested two parameters regarding the meat quality of beef cattle to understand how the poor inspection affects the quality of the final product. Therefore, 12 samples of the longissimus dorsi muscle were evaluated from different butcheries, using fresh meat recently received by the supplier. There were no sanitary inspection records related to the sampled meat. The results showed a large percentage of PSE (pale, soft, and exudative) and DFD (dark, firm, and dry) meats. Given the pH and color values, it is concluded that the slaughtering was not carried out properly. Hence, technological defects in the meat were observed, making it inappropriate for consumption. We concluded that inefficient pre-slaughter handling is compromising animal welfare, increasing the biosecurity risk, and impairing the quality of the final product. We argue that these problems not only decrease the sustainability of livestock systems but also compromises human health. Currently, livestock plays an important role in global environmental concerns, such as climate change, land degradation, water pollution and biodiversity loss. Then, it is needed to reduce the waste of such products.