Microbial colours with different shades like pink (Rhodotorula), red (Chromobacterium), yellow (Sarcina) and light yellow (Micrococcus) using apple pomace (a waste from apple juice) were produced by solid state fermentation, characterized and modified into water soluble pigments. Biocolour from Rhodotorula had maximum absorption in ethanol, hexane and acetone at 200–550 nm with λ-max between 480 and 490 nm. In case of Chromobacterium sp., ethanol, petroleum ether and hexane gave the highest absorption between 520 and 540 nm (narrow range). Pigment of Micrococcus sp., had maximum absorption between 200 and 400 nm with λ-max in narrow range (400–600 nm) scanning between 480 and 490 nm in ethanol. Dark yellow colour pigment of Sarcina gave the maximum absorption between 200 and 500 nm in ethanol. All the biocolours examined were carotenoids, insoluble in water and thus, have limited applications in food. Aminoacid, benzoic acid and gelatin were employed to make these pigments water soluble by reflexing at different pH values viz., 3, 7 and 9.2 for each pigment. Maximum conversion (51 %) of pigment of Rhodotorula occurred using gelatin at pH 9.2. In case of Chromobacterium using amino acetic acid at pH 9.2 it was 60 %. It was 55 and 56 % at pH 7 and 3, respectively. In Sarcina, at pH 9.2 maximum conversion (48 %) took place using amino acetic acid, whereas in pigment of Micrococcus sp. 40 % conversion took place using amino acetic acid at pH 9.2 and the minimum conversion occurred using amino benzoic acid at pH 3. It is concluded that the pigments produced by Rhodotorula, Micrococcus and Chromobacterium can be modified chemically to make them water soluble thus, making possible their use in various food products.

Food industry in general, generates a large quantity of waste (i.e. peel, seed, pomace, rags, kernels, etc.) which is biodegradable in nature. Due to richness in carbohydrates, dietary fibres and minerals, such wastes have the potential to support the growth of microorganisms involved in the production of various products. Laboratory scale solid state fermentation (SSF) of waste from apple processing industry revealed the possibility of production of several value added products. Solid state fermentation of apple pomace by Saccharomyces cerevisiae and removal of ethanol followed by drying increase the nitrogen and fat content in the fermented and dried apple pomace for use as an animal feed. S. cerevisiae, in sequential interactive culture improve the soluble protein content of the fermented apple pomace. The product (animal feed) could successfully be fed to the poultry after mixing with standard feed in the ratio of 1:1. SSF of apple pomace using Aspergillus niger yield pectin esterase enzyme much more than submerged fermentation. Production of different biocolours by fermentation with Chromobacter sp., Sarcina sp., Rhodotorula sp. and Micrococcus sp. is possible along with citric acid production in SSF by A. niger, all having commercial value. Apple pomace utilization can become a model for the value addition of similar wastes and development of solid state fermenter and downstream processing will go a long way in developing technology from laboratory to pilot scale. In the present paper authors have summarized various research reports and their work on solid state fermentation of apple pomace and the production of value added products.

The effect of carbon and nitrogen sources on yield and carotenoid production by Chromobacter sp. - a dark red colour producing bacteria was studied in apple pomace based medium. Apple pomace at a concentration of 20 g/l has shown maximum yield of biomass and carotenoids in the basic medium. The use of maltose (0.3%) in the apple pomace based medium gave the highest yield of biomass (6.6 g/l) and carotenoids (46.3 mg/100 g). Potassium nitrate (0.1%) gave maximum production of biomass (6.5 g/l) and carotenoids (46.6 mg/100 g), pH 6.0 was optimum, and incubation temperature of 35 degrees C. produced the highest carotenoids. Incubation period of 48 h has shown higher yield of biomass and carotenoids.

The baker's yeast (Saccharomyces cerevisiae var. diastaticus) was grown on apple pomace extract, molasses and jaggery in variable fed batch cultivation system in order to study the effect of different carbon sources on the production and fermentation characteristics. The fermentation conditions were pH 4.5, temperature 30 degrees C, dissolved oxygen (DO) 20 per cent with agitation ranging between 50-450 rpm depending upon the DO concentration in the medium. The highest total cell biomass yield was found in apple pomace extract based medium followed by molasses or jaggery, along with lowest generation time. General appearance of wet compressed yeast was also influenced by the type of substrate used. No appreciable difference in the dough raising capacity (DRC) of the produced yeast compared to the commercial yeast was evident. These findings demonstrate that apple pomace is a comparable energy source for the production of baker's yeast.

In India, an impressive progress has been made in development of technologies for preparation of wines from grapes, mango, apple, peach, pear, plum, cashew-apple, pineapple, pomegranate, banana, ber, strawberry, and kinnow. Screening of cultivars of grapes, peach, plum, mango,apple, wild and cultivated apricot, litchi, sand pear and strawberry has also been made for wine preparation. Methods for the cider and wine including those with medicinal properties preparation from apple juice and its concentrate have been standardized keeping, in view the characteristics of local produce and taste. Techniques based on debittering of juice by adsorption on XAD-16 and thermovinification of kinnow and strawberry wines have been developed. Technology for vermouth has been developed from plum, apple and sand pear fruits. Deacidifying yeast (Schizosaccharomyces pombe) for making dry. wine of acceptable quality and production of sparkling wines from plum, using immobilized S. pombe and foam stabilization by the use of yeast extract has successfully been made. An overview of the wine research, however, reflects that sporadic and inconsistent work is being carried out at different places in India and there are still a large number of research gaps. Consequently, the Indian wine industry is still in infancy and has to imbibe many developments made world over in the wine production.