Innovations in Indian Fermented Milk Products — A Review

"Ethno-microbiology" of ethnic Indian fermented foods and alcoholic beverages

The concept of "ethno-microbiology" is to understand the indigenous knowledge of the Indian people for production of culturally and organoleptically acceptable fermented foods by natural fermentation. About 1000 types of common, uncommon, rare, exotic and artisan fermented foods and beverages are prepared and consumed in different geographical regions by multi-ethnic communities in India. Indian fermented foods are mostly acidic and some are alkaline, along with various types of alcoholic beverages. A colossal diversity of microorganisms comprising bacteria mostly belongs to phylum Firmicutes, filamentous moulds and enzyme- and alcohol-producing yeasts under phyla Ascomycota and Mucoromycota, and few bacteriophages and archaea have been reported from Indian fermented foods. Some microorganisms associated with fermented foods have functionalities and health promoting benefits. "Ethno-microbiology" of ethnic Indian people has exhibited the proper utilisation of substrates either singly or in combination such as fermented cereal-legume mixture (idli, dosa and dhokla) in South and West India, sticky fermented soybean food (kinema and related foods), fermented perishable leafy vegetable (gundruk and related foods), fermented bamboo shoots (soibum and related foods) and fermented fish (ngari and others) in North East India, and fermented meat and sausage-like products in the Indian Himalayas, fermented coconut beverage (toddy) in coastal regions, and various types of naturally fermented milk products (dahi and related products) in different regions of India. This review has also highlighted the "ethno-microbiology" knowledge of the people involving the consortia of essential microorganisms in traditionally prepared amylolytic starters for production of cereal-based alcoholic beverages. The novelty of this review is the interpretation of ethno-microbiological knowledge innovated by ethnic Indian people on the use of beneficial microorganisms for food fermentation to obtain the desired fermented food products for consumption.

Improvements in makkhan (traditional Indian cultured butter) production: a review

Since Vedic times, traditional Indian cultured butter or makkhan has been one of the most demanding and extensively used food items in the village households of Indian subcontinent. Its processing and overall quality suffers due to the use of conventional practices, which has probably discouraged the production of product in organized sectors. No scientific intervention has taken place to improve the product quality and process since the inception of makkhan making. As an initiative towards the improvement, the present study is focused to prepare a detail scientific background on chemistry, quality attributes, utilization, preparation methods, and storage of product for identifying challenges and scopes of overall improvement in production status. To validate the opportunities identified for the improvements in production various approaches especially mechanized approaches are suggested in this review.

Conjugated linoleic acid enriched skim milk prepared with Lactobacillus fermentum DDHI27 endorsed antiobesity in mice

Aim: This study evaluated the antiobesity effect of skim milk prepared with conjugated linoleic acid producing probiotic Lactobacillus fermentum DDHI27 (PCLA). Materials & methods: C57BL/6 J mice were divided into five groups, and different obesity-associated parameters were studied. Results: PCLA supplementation alleviated body weight, epididymal and mesenteric fats and improves lipid profiles. Significant ameliorations in leptin, blood glucose, hepatic steatosis and reduction in adipocytes size were also observed. Additionally, feeding also led to positive alterations in the adipogenesis transcription factors and key lipogenesis genes. Improvement in the gut microbiota dysbiosis was also revealed. Conclusion: Results inferred that PCLA exerted an antiobesity effect in diet-induced obese mice and may be further developed in the functional foods for the management of obesity.

Bacterial community in naturally fermented milk products of Arunachal Pradesh and Sikkim of India analysed by high-throughput amplicon sequencing

Naturally fermented milk (NFM) products are popular ethnic fermented foods in Arunachal Pradesh and Sikkim states of India. The present study is the first to have documented the bacterial community in 54 samples of NFM products viz. chhurpi, churkam, dahi and gheu/mar by high-throughput Illumina amplicon sequencing. Metagenomic investigation showed that Firmicutes (Streptococcaceae, Lactobacillaceae) and Proteobacteria (Acetobacteraceae) were the two predominant members of the bacterial communities in these products. Lactococcus lactis and Lactobacillus helveticus were the predominant lactic acid bacteria while Acetobacter spp. and Gluconobacter spp. were the predominant acetic acid bacteria present in these products.

Some Technological Properties of Lactic Acid Bacteria Isolated from Dahi and Datshi, Naturally Fermented Milk Products of Bhutan

Dahi and datshi are common naturally fermented milk (NFM) products of Bhutan. Population of lactic acid bacteria (LAB) in dahi (pH 3.7) and datshi (pH 5.2) was 1.4 × 107 and 3.9 × 108 cfu/ml, respectively. Based on 16S rRNA gene sequencing isolates of LAB from dahi and datshi were identified as Enterococcus faecalis, E. faecium, Lactococcus lactis subsp. lactis. LAB strains were tested for some technological properties. All LAB strains except E. faecalis CH2:17 caused coagulation of milk at both 30°C for 48 h. Only E. faecium DH4:05 strain was resistant to pH 3. No significant difference (P > 0.05) of viable counts was observed in MRS broth with and without lysozyme. All LAB strains grew well in 0.3% bile showing their ability to tolerate bile salt. None of the LAB strains showed >70% hydrophobicity. This study, being the first of its microbiological analysis of the NFM of Bhutan, has opened up to an extent of research work that gives a new insight to the products.

Fortification of dahi (Indian yoghurt) with omega-3 fatty acids using microencapsulated flaxseed oil microcapsules

The objective of the study was to develop and characterize omega-3 dahi (Indian yoghurt) through fortification of microencapsulated flaxseed oil powder (MFOP). Four different formulations of MFOP were fortified in dahi @ 1, 2 and 3 % levels and the level of addition was optimized on the basis of sensory scores. Dahi fortified at 2 % level was observed comparable to control, which was further studied for titratable acidity, syneresis, firmness, stickiness, oxidative stability (peroxide value), α-linolenic acid (ALA, ω-3) content and sensory attributes during 15d of storage. MFOP fortified dahi showed significantly (p < 0.05) higher acidity and percent syneresis after 12d of storage. However, peroxide value remained well below (~0.41) to the maximum permissible limit (5 meq peroxides/kg oil) prescribed by Codex Alimentarius Commission (1999). Gas-liquid chromatography profile showed ~21 % decrease in ALA content in fortified dahi after 15d of storage. Overall, it can be concluded that flaxseed oil microcapsules could be successfully incorporated in dahi; which could serve as a potential delivery system of omega-3 fatty acids.

Review: Diversity of Microorganisms in Global Fermented Foods and Beverages

Culturalable and non-culturable microorganisms naturally ferment majority of global fermented foods and beverages. Traditional food fermentation represents an extremely valuable cultural heritage in most regions, and harbors a huge genetic potential of valuable but hitherto undiscovered strains. Holistic approaches for identification and complete profiling of both culturalable and non-culturable microorganisms in global fermented foods are of interest to food microbiologists. The application of culture-independent technique has thrown new light on the diversity of a number of hitherto unknown and non-cultural microorganisms in naturally fermented foods. Functional bacterial groups ("phylotypes") may be reflected by their mRNA expression in a particular substrate and not by mere DNA-level detection. An attempt has been made to review the microbiology of some fermented foods and alcoholic beverages of the world.