Fermented fruits and vegetables of Asia: a potential source of probiotics.

As world population increases, lactic acid fermentation is expected to become an important role in preserving fresh vegetables, fruits, and other food items for feeding humanity in developing countries. However, several fermented fruits and vegetables products (Sauerkraut, Kimchi, Gundruk, Khalpi, Sinki, etc.) have a long history in human nutrition from ancient ages and are associated with the several social aspects of different communities. Among the food items, fruits and vegetables are easily perishable commodities due to their high water activity and nutritive values. These conditions are more critical in tropical and subtropical countries which favour the growth of spoilage causing microorganisms. Lactic acid fermentation increases shelf life of fruits and vegetables and also enhances several beneficial properties, including nutritive value and flavours, and reduces toxicity. Fermented fruits and vegetables can be used as a potential source of probiotics as they harbour several lactic acid bacteria such as Lactobacillus plantarum, L. pentosus, L. brevis, L. acidophilus, L. fermentum, Leuconostoc fallax, and L. mesenteroides. As a whole, the traditionally fermented fruits and vegetables not only serve as food supplements but also attribute towards health benefits. This review aims to describe some important Asian fermented fruits and vegetables and their significance as a potential source of probiotics.

Yersinia enterocolitica: Mode of Transmission, Molecular Insights of Virulence, and Pathogenesis of Infection.

Although Yersinia enterocolitica is usually transmitted through contaminated food and untreated water, occasional transmission such as human-to-human, animal-to-human and blood transfusion associated transmission have also identified in human disease. Of the six Y. enterocolitica biotypes, the virulence of the pathogenic biotypes, namely, 1B and 2-5 is attributed to the presence of a highly conserved 70-kb virulence plasmid, termed pYV/pCD and certain chromosomal genes. Some biotype 1A strains, despite lacking virulence plasmid (pYV) and traditional chromosomal virulence genes, are isolated frequently from humans with gastrointestinal diseases similar to that produced by isolates belonging known pathogenic biotypes. Y. enterocolitica pathogenic biotypes have evolved two major properties: the ability to penetrate the intestinal wall, which is thought to be controlled by plasmid genes, and the production of heat-stable enterotoxin, which is controlled by chromosomal genes.

Optimization of thermostable á- amylase production by Streptomyces erumpens MTCC 7317 in solid-state fermentation using cassava fibrous residue

Production of á- amylase under solid state fermentation by Streptomyces erumpens MTCC 7317 was investigated using cassava fibrous residue, one of the major solid waste released during extraction of starch from cassava (Manihot esculenta Crantz). Response surface methodology (RSM) was used to evaluate the effect of the main variables, i.e., incubation period (60 h), moisture holding capacity (60 percent) and temperature (50(0)C) on enzyme production by applying a full factorial Central Composite Design. Varying the inoculum concentration (5-25 percent) of S. erumpens showed that 15 percent inoculum (v/w, 2.5 x 10(6) CFU/ml) was the optimum for á- amylase production. Among the different nitrogen sources supplemented, beef extract was most suitable for enzyme production. The application of S. erumpens enzyme in liquefaction of soluble starch and cassava starch was studied. The maximum hydrolysis of soluble starch (85 percent) and cassava starch (70 percent) was obtained with the application of 5 ml crude enzyme (17185 units) after 5 h of incubation.

Lactic acid production from cassava fibrous residue using Lactobacillus plantarum MTCC 1407.

During extraction of starch from cassava, fibrous residue is a major waste released into the environment. Owing to the high starch content (60-65% on dry weight basis) and organic matter of cassava fibrous residue (CFR), an attempt has been made to utilize it for the production of lactic acid (LA) in semi solid state fermentation using Mann Rogassa Sharpe medium containing [5 % (wv(-1))] CFR in lieu of glucose [2% (wv(-1))] as the carbon source. Response Surface Methodology (RSM) was used to evaluate the effect of main variables, i.e. incubation period, temperature and pH on LA production. The experimental results showed that the optimum incubation period, temperature and pH were 120 hr 35 degrees C and 6.5, respectively. Maximum starch conversion by Lactobacillus plantarum MTCC 1407 to LA was 63.3%. The organism produced 29.86 g of (L+) LA from 60 g of starch present in 100 g of CFR. The LA production yield (i.e. mass LA produced mass starch present in CFR(-1) x 100) was 49.76%.