Hoda Ghayomi; Mohammad Ali Najafi; Naser Soltani Tehrani; Mohammad Rahnama
Abstract
Biodegradable films containing lactic acid bacteria (LAB) are considered as new tools for advanced methods of food storage. In this study, Lactobacillus casei ATCC 39392 (L. casei 39392) was directly incorporated into a film formation solution of sodium caseinate (NaCas) and methyl cellulose (MC). The ...
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Biodegradable films containing lactic acid bacteria (LAB) are considered as new tools for advanced methods of food storage. In this study, Lactobacillus casei ATCC 39392 (L. casei 39392) was directly incorporated into a film formation solution of sodium caseinate (NaCas) and methyl cellulose (MC). The bioactive films were prepared in a manner to contain 106CFU/cm2 L. casei 39392. The moisture content, solubility in water, water vapor permeability (WVP), color, opacity, tensile strength, percentage of elongation at break, and the elastic modulus of the films were studied. The survival rate of L. casei 39392 was examined during 30 days of storage (5 °C, RH 75%) and the films inhibitory effect on the growth of Pseudomonas aeruginosa PTCC 10832 was also studied at 5 °C for 12 days. The presence of L. casei 39392 increased the film’s opacity and its WVP compared to the control (p ˂ 0.05). The survival rate of L. casei 39392 was higher in NaCas films than in methylcellulose films (p < 0.05). A higher inhibitory effect on the growth of P. aeruginosa 10832 (85.3%) was observed in the MC bioactive film, and this inhibitory effect became noticeable from the fourth day of storage onwards (p ˂ 0.05). Our results showed that the bioactive films containing L. casei 39392 could be used and recognized as biofilms containing natural preservatives.
Elnaz Milani; Hajar Naeemi; Seyed Ali Mortazavi; Arash Koocheki
Abstract
In this study, symbiotic yog-ice (rozen yogurt) was produced that was inoculated with different levels of inulin(0,2.5 amd 5%)as prebiotic compound and Lactobacillus Casei as probiotic bacteria in two types; free and encapsulated with Sodium Algint-Whey Protein Concentration for low fat yog-ice cream.The ...
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In this study, symbiotic yog-ice (rozen yogurt) was produced that was inoculated with different levels of inulin(0,2.5 amd 5%)as prebiotic compound and Lactobacillus Casei as probiotic bacteria in two types; free and encapsulated with Sodium Algint-Whey Protein Concentration for low fat yog-ice cream.The survivability of this probiotic bacteria was evaluated under simulated gastro-intestinal conditions ,during 30 days storage at -18oC. In the samples with free state of probiotic bacteria, the number of viable cells ,after 1h exposuring simulated gastric juice(pH=2,pepcine) decreased from 9.78-9.81 log cfu/ml to 6.97-7.26 log cfu/ml,at the end of 30 days storage at -18oC,while, the viable number of encapsulated state of probiotic bacteria, after 1h exposuring simulated gastric juice, decreased from 8.15-8.66 log cfu/ml to 6.80-7.09 log cfu/ml at the end of 30 days storage at -18oc.After exposuring simulated gastric juice, samples was ezposured 2.5h under simulated intestinal juice(pH=7.4,panceratin), and the results that was gained showed that, the samples containing free probiotic bacteria after 2.5h exposuring simulated intestinal juice decreased from 8.808-9.355 log cfu/ml to 5.159-5.9 log cfu/ml at the end of 30 days storage at -18oC.While, in the samples containing sodium alginate-whey protein concentration capsules, the viable number of cells decreased from 7.38-8.201 log cfu/ml to 6.151-6.672 log cfu/ml, at the end of 30 days storage at -18oC. The results indicate that there are significant differences (p
