Research in the field of food science and technology has shown that bacteria can communicate with each other. This communication is population-density dependent and involves signalling molecules that can diffuse between the bacterial cells. The process of communication is called ‘quorum sensing’.

Quorum sensing is now known to be a widespread phenomenon responsible for modulating many different activities in diverse Gram-negative and Gram-positive bacteria. This phenomenon has been found to be responsible in food spoilage and biofilm formation by food-related bacteria in the food

industry in addition to pathogenesis. Understanding bacterial quorum-sensing systems can help in controlling the growth of undesirable food-related bacteria. Blocking the quorum-sensing signalling molecules in food related bacteria may possibly prevent quorum-sensing-regulated phenotypes

responsible for food spoilage. With proper understanding of quorum sensing mechanism we can identify quorum-sensing inhibitors that could be used as food preservatives to enhance food safety and increase shelf life.

The extractive constituents, which are known as taste active components of fisheries products in many research works have been reviewed..This review found glutamate, glycine, alanine, arginine, proline, valine, methionine, phenylalanine, tyrosine, inosine 5’-monophosphate (IMP), adenosine 5’-

monophosphate (AMP), guanosine 5’-monophosphate (GMP), trimethylamine, trimethylamine oxide (TMAO), glycine betaine, lactate, succinate as important contributors to the taste of raw and processed

fisheries products. Sweet, salty, bitter, sour, and umami are the basic tastes, defined by these taste active components. Sweet taste is imparted by glycine, alanine, TMAO while bitter taste by arginine and other hydrophobic amino acids. Glutamate has a role in sour taste, and contributes to umami taste

through synergetic effects in co-existence of IMP, GMP and AMP. The large amount of alanine or glutamate suppresses the sweetness effect of glycine through antagonistic effect. However, these taste-producing components vary with species, environments, various processing methods and relative

quantities among them.

Food processing industry including fruit and vegetable processing is the second largest generator of wastes into the environment only after the household sewage. The generation of biodegradable waste increased linearly with the growth and development of food processing industry. A huge

amount of waste in the form of liquid and solid is produced in the fruit and vegetable processing industries is valuable but biodegradable natural resources with large economic potential. It causes pollution problem if not utilized or disposed-off properly. The waste obtained from fruit processing

industry is extremely diverse due to the use of wide variety of fruits and vegetables, the broad range of processes and the multiplicity of the product. Different fruits and vegetable possess various quantities of waste. Waste product which is thrown into the environment has a very good antimicrobial

and antioxidant potentiality. These are novel, natural and economic sources of antimicrobics and antioxidants, which can be used in the prevention of diseases caused by pathogenic microbes. These all benefits will open up as a scope for future utilization of the waste for therapeutic purpose. However,

lack of pilot testing of the developed technologies, negative attitude of the industrialists and perhaps, less helping hand from the government sector are the major constraints in utilization of the waste.

Freeze-drying is a process which retains the nutritional, sensorial and functional qualities of foods,together with extreme reduction in weight, high solubility, long shelflife at moderate temperature and the possibility to perform rehydration at any desired level. The application of this technique in the

development of a Freeze dried mango milk shake powder using Badami mango (Mangifera indica L) pulp, milk (3.0g/100g fat, 8.5g/100g Solids Non Fat), nuts, flavourants and ascorbic acid to deliver RDA level of ascorbic acid and β-carotene was hence attempted. Optimized formulations were subjected to freeze drying for better storage stability. The water activity was found to be 0.22 and BET monolayer value 2.294g/100g solids. β-Carotene, ascorbic acid and oxidative rancidity profile monitored at ambient (28±2°C) and 37°C storage revealed no significant differences (p>0.01) at ambient temperature in ascorbic acid and thiobarbituric acid reactive substances (TBARS) but significant difference (p<0.01) was observed after storage at 37°C. Significant degradation of β-carotene was observed after 12 and 6 months of storage at ambient (28±2°C) and 37°C respectively. Total fatty acid profile by gas chromatography indicated the presence of saturated, monounsaturated and polyunsaturated fatty acids (PUFA) in the ratio of 1:0.51:0.28. PUFA like linoleic, linolenic and arachidonic were significantly (p<0.01) affected by 6 months of storage at 37°C. Organoleptically, the product was rated 7.60±0.10 and 7.49±0.09 under ambient and 37°C after 12 and 6 months storage respectively indicating good overall acceptability on a 9 point hedonic scale.

Attempt made to prepare and evaluate wines from different citrus fruits viz; mandarin, orange, kinnow and galgal is reported here. The must from kinnow fruits had the highest rate of fermentation while that of galgal recorded the lowest. Wines from different citrus fruits differed for various physio-chemical

characteristics like aldehyde, colour, ethanol, pH and titrable acidity. All the wines except that of galgal were comparable in various physico-chemical characteristics TSS, pH and titratable acidity. All the wines recorded a score of more than 12 for their sensory qualities thus these were found to be

acceptable. On the basis of Quantitative Descriptive Analysis (QDA), it was concluded that orange and kinnow wines were rich in characteristic flavour of the respective citrus fruits. While high variations in other characteristics like alcoholic, aromatic were recorded, the descriptors like sweet, molasses,

yeasty, musty were comparable. Bitterness was perceptible in all the citrus wine though the exten varied. It is concluded that out of various citrus wines, those from mandarin and orange were more acceptable than others on the basis of sensory score.

The demand of GRAS food biopreservatives is rising day by day. and food industry is facing these challenges to provide naturally preserved foods with better consumer acceptability. Bacteriocins produced by lactic acid bacteria especially Lactococcus lactis and Pediococcus acidilactici offer the

possibility of preventing food spoilage and improving counts of desirable bacteria in fermented foods. Pediocin CP2, a member of class IIa bacteriocin family, was engineered and expressed in E. coli BL21(DE3). Studies carried out to assess the stability and biopreservative effect of recombinant

pediocin CP2 in some model food systems is reported. It was tested for biopreservation of spiked model food systems viz. a viz. black gram and mung bean sprouts, milk, minced meat, and vegetable fresh fruit cuts. Results indicated a gradual loss of pediocin activity with respect to time and nature of

food material. Residual rec-pediocin alone exhibited a significant biopreservative effect ranging from 17 to 37% growth reduction of indicator organism in the absence of other antimicrobial factors and upto a maximum of 63% in combination with sodium citrate in the assayed time period. Results have clearly the potential of rec-pediocin in combination with chemical antimicrobial compounds in prolonging the shelf life of foods prone to microbial spoilage.

In view of the increasing demand of value added herbal products, an attempt was made to produce a functional fermented Aloe vera based herbal wine. The wine was evaluated for effect on probiotics and food borne pathogens. Aloe vera gel, supplemented with sugar proved to be a good medium for

the growth of Saccharomyces cerevisiae for making the Aloe vera wine. The wine was found to be similar to any other wine in terms of its composition, and sensory quantities. The wine exhibited bactericidal activity against common food borne pathogens ( Salmonella typhimurium, Staphylococcus

aureus, Escherichia coli). However, its bactericidal effect was much faster in case of Salmonella as compared to other pathogens. Interestingly, the wine was not inhibitory to the selected probiotic strains and no significant difference in the viable count of lactobacilli was found in the fecal matter, hence, indicating their persistence in the gut of wine fed animal.

Wine was prepared from tendu (Diospyros melanoxylon L.) fruits and evaluated. Must from tendu fruits was made by raising total soluble solids (TSS) to 20° B, 0.1% (NH₄) SO₄ as nitrogen source and fermenting it using 2% Saccharomyces cerevisiae var. ellipsoideus into wine. The wine had the

following proximate compositions: TSS, 2°B; total sugar of 3.78g/100ml; titratable acidity, 1.32g tartaric acid/ 100ml; pH, 3.12; total phenolics, 0.95g/100ml; β-carotene, 8µg/100ml; ascorbic acid, 1.52mg/100ml; lactic acid, 0.39mg/100ml, methanol, 3.5% (v/v) and ethanol,6.8% (v/v). The tendu wine had a 2,2-diphenyl-1-picrylhydrazyl (DPPH )scavenging activity of 52% at a dose of 250µg/ ml. Principal Component Analysis(PCA) reduced the 10 original analytical and proximate variables (TSS, total sugar, TA, pH, phenol, β-carotene, ascorbic acid, lactic acid, ethanol and DPPH scavenging activity)

into three independent components that accounted for 83.42% of the total variations. Sensory evaluation was carried out by 16 trained panelists on various attributes such as taste, aroma, flavour, colour/ appearance and after-taste. The analysis showed that the taste of tendu wine was liked strongly by

the panelists and there was no significant difference between the two replicate sets (p<0.05) in most sensory parameters.

Bhatooru is a cereal based traditional fermented food of Himachal Pradesh prepared by fermentation of wheat flour dough by sourdough starter ‘malera’. Bhatooru was prepared in laboratory by using yeast and lactic acid bacteria or combination of these microorganisms as starter. Bhatooru fermentations

carried out by the combination of starters (C1 and C2) had higher protein content than other samples.Total sugar level in these samples decreased and reducing sugar level increased during fermentation. However, the starch content in these samples decreased. With the progress in fermentation, the

amylase and protease activity also increased in almost all the samples except control where very little activity was observed from 0-10 h.It was observed that B-vitamin content (thiamin, riboflavin, nicotinic acid and cyanocobalamin) in samples were higher as compared to the control. Out of various yeast

strains used, Saccharomyces cerevisiae inoculated samples showed higher vitamin content. Thiamin content was relatively higher in samples prepared from Lactobacillus strains and combination of starters. Increase in essential amino acid contents (methionine, phenylalanine, threonine, lysine and leucine) was observed in the bhatooru dough prepared by using combination of starters.

BThe present study aimed at sequential optimization of culture conditions for the enhanced production of xylanase from indigenously isolated Acinetobacter sp. by solid state fermentation. Among various agro-industrial residues utilized wheat bran was found to be the best. Various fermentation parameters

for xylanase production were optimized using one factor at a time method. At the end of 72 hours,maximum enzyme activity (7.52 U/gds) was obtained using wheat bran with 75 % moisture content. Xylanase titres were further improved to 27.68U/gds using L9(34) orthogonal array method. Thus, approximately a four-fold increase in xylanase activity was achieved suggesting that newly isolated strain is an efficient xylanase producer.

The produce bio-fuel ( ethanol) from cassava waste water using fungal enzymes from Aspergillus niger and Rhizopus oryzae, synthetic diastase enzyme; and to compare the fermentation of the various cassava specie is reported. Ethanol was produced from cassava effluents of four varieties of

cassava: Type I (NR 8082), Type 2 (TMS 92/00057), Type 3 (NR 87184) and Type 4 (TMS 30572) using amylase enzyme produced from Aspergillus niger, Rhizopus oryzae and synthetic diastase. Type I and III varieties produced 30% each of total distillate volume yield, while Type II and IV produced 20% each of total distillate volume yield. Treatment of cassava effluent samples with Rhizopus oryzae gave overall ethanol distillate volume yield of 62%, followed by Aspergillus niger 25% and diastase 13%.

A combination of cassava effluent Type and enzyme treatment R3 gave significantly (p<0.05) the largest ethanol volume of 164.0±1.0 ml with a total percentage yield of 79%. Though A1 (Aspergillus niger fermentation of Cassava Type I-NR 8082), followed closely with 123.0±2.5 ml, it had a comparatively lower percentage yield of 58% compared to R2 and R4 with 69% and 70% total per cent yield of ethanol, respectively. Thus ,the source of biochemical enzyme could be a determining factor in the percentage

yield and volume of ethanol distillate produced rather than the choice of cassava specie.

Experiments were conducted to develop the fruit jelly using various level of guava extract and carrot juice content Viz. ,75:25, 50:50 and 25:75. The prepared fruit jelly filled in jars was labeled and stored at room temperature upto 90 days to determine the physico-chemical and sensory quality attributes. Evaluation for fresh as well as stored samples was done at an interval of 15, 30, 45, 60, 75 and 90 days of storage at room temperature (370C). The maximum overall acceptability score for the fresh product

prepared with the amount of guava extract and carrot juice level of 75:25 was awarded as 7.8 (like moderately). It was concluded that fruit jelly prepared with guava extract and carrot juice ratio of 75:25 was found to be superior to those prepared with other ratios.In general ,there was decrease in most of

physico-chemical and sensory qualities during the storage.