Abstract: Freshly prepared apple tea wine (a combination of tea extract and apple juice) is having yeasty and dull flavour, which needs to be improved to increase the acceptability of this product. Therefore, an attempt has been made for artificial ageing of apple tea wine using different wood chips to improve its physico-chemical, sensory and antimicrobial attributes. Different types of wood chips (Quercus spp., Bombax spp. and Acacia spp.) were added respectively (2.5 g/L to the freshly prepared apple tea wine) and allowed for ageing in carboys for the six months at the room temperature. The influence of each wood species on physico-chemical, sensory and antimicrobial attributes was tested upto 6 months of storage. Storage intervals significantly affected all the physico-chemical attributes (except total sugars, volatile acidity, and antioxidant activity), whereas, the addition of wood chips affected titratable acidity, ethanol, higher alcohols, total phenols, and amino acid. Cluster analysis of the physico-chemical attributes data revealed the same and showed that storage intervals exerted more effect on the physico-chemical and antimicrobial properties of the apple tea wine rather than the wood chips. The antimicrobial activity of 6 months aged wine was low as compared to the fresh wine. Among all the wood chips, apple tea wine aged with Quercus spp. possesses a significantly higher score (according to desirability) than the wine aged with other wood chips and control. In nutshell, apple tea wine matured with Quercus spp. wood chips for 6 months were the best with improved physico-chemical and sensory attributes.

In the present study, a bacterium isolated from Marcha- a herbal cake used as traditional starter culture to ferment local wine in North East India, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. Listeria monocytogenes MTCC 839, Bacillus subtilis MTCC 121, Clostridium perfringens MTCC 450, Staphylococcus aureus, Lactobacillus plantarum and Leuconostoc mesenteroides MTCC 107 by using bit/disc method followed by well diffusion method. The bacterial isolate was identified as Brevibacillus borstelensis on the basis of phenotypic, biochemical and molecular characteristics using 16Sr RNA gene technique. Bacteriocin like inhibitory substance produced by Brevibacillus borstelensis AG1 was purified by gel exclusion chromatography. The molecular mass of the Brevibacillus borstelensis AG1 was found to be 12 kDa. Purified bacteriocin like inhibitory substance of Brevibacillus borstelensis was further characterized by studying the effect of temperature, pH, proteolytic enzyme and stability. Bacteriocin like inhibitory substance was found to be thermostable upto 100 °C, active at neutral pH, sensitive to trypsin, and partially stable till third week of storage thus showing a bright prospective to be used as a potential food biopreservative.

Aspergillus niger F7 isolated from soil was found to be the potent producer of cellulase and xylanase. The residue of forest species Toona ciliata, Celtris australis, Cedrus deodara and Pinus roxburghii was selected as substrate for biodegradation study due to its easy availability and wide use in industry. It was subjected to alkali (sodium hydroxide) treatment for enhancing its degradation. Biodegradation of forest waste by hydrolytic enzymes (cellulase and xylanase) secreted by A. niger under solid state fermentation (SSF) was explored. SSF of pretreated forest biomass was found to be superior over untreated forest biomass. Highest extracellular enzyme activity of 2201±23.91 U/g by A. niger was shown in pretreated C. australis wood resulting in 6.72±0.20 percent hydrolysis and 6.99±0.23 biodegradation index (BI). The lowest BI of 1.40±0.08 was observed in untreated saw dust of C. deodara having the least enzyme activity of 238±1.36 U/g of dry matter. Biodegradation of forest biomass under SSF was increased many folds when moistening agent i.e. tap water had been replaced with modified basal salt media (BSM). In BSM mediated degradation of forest waste with A. niger, extracellular enzyme activity was increased up to 4089±67.11 U/g of dry matter in turn resulting in higher BI of 15.4±0.41 and percent hydrolysis of 19.38±0.81 in pretreated C. australis wood. A. niger exhibited higher enzyme activity on pretreated biomass when moistened with modified BSM in this study. Statistically a positive correlation has been drawn between these three factors i.e. enzyme activity, BI and percent hydrolysis of forest biomass thus proving their direct relationship with each other.