Band 2, Heft 4

Rice bran is a primary by-product of the traditional rice processing industry. Once oil is extracted from rice bran, the left over residue is called de oiled rice bran (DOB). Its disposal presents economic and environmental problems. Microbial conversion of DOB into single cell protein (SCP) is an innovative practical approach for protein supplementation of a staple diet. The present research was undertaken to test the growth of industrially important fungi, Aspergillus oryzae MTCC 1846 on DOB through solid state fermentation (SSF) technology. Various process parameters effect such as moisture, pH of the substrate, inoculum size, temperature and nitrogen source for maximum protein enrichment were studied. The optimum conditions for the enrichment process were found to be moisture content 60%; temperature 280C; pH 6.0; inoculum’s concentration 109 spores/ g substrate and particle size of DOB, 0.3 mm. Among the various nitrogen source tested, ammonium sulfate (0.6% w/w) showed maximum protein enrichment (24.30%) followed by vegetable + fruit waste extract (23.50%) and legume root extract (23.10%).

In this study, microemulsion cross-linking treatment was used on food grade potato and maize starches for preparing micro starch particles. Laser diffraction technique was introduced to measure the particle size characteristics, including the median particle diameter (d 50), surface area mean diameter D [3, 2], volume mean diameter D [4, 3] and specific surface area of micro potato and maize starch particles. The volume distributions and number distributions were also analyzed using Mastersizer 2000 Software. The d 50, D [3, 2], D [4, 3] of the potato starch granules were reduced significantly (p < 0.05) after the microemulsion cross-linking reaction and ball-milling treatment. However, the microemulsion cross-linking treatment did not produce significant changes in the particle size characteristics of the maize starch samples.

Gelatinisation and retrogradation of starch-whey mixtures were studied in water (pH 7) using the Rapid Visco-Analyser (RVA). The starch:whey ratios ranged from 0:100 – 100:0. Wheat starch, and whey protein concentrate (about 80% solids basis) and isolate (about 96% solids basis) were used. Mixtures with whey isolates were generally more viscous than those with whey concentrates, and this was attributed to fewer non-protein milk components in the former. Whey protein concentrates and isolates reduced the peak, trough and final viscosities of the mixtures, but the breakdown and setback ratios of the mixtures were increased. The gelatinisation temperature increased with whey substitutions indicating that whey protein delayed starch gelatinisation. The temperature of fastest viscosity development decreased as the amount of whey was increased. Whey protein isolate generally exercised a lesser effect than the concentrate. At between 40 - 50% whey substitutions, the dominant phase changed from starch to protein irrespective of the source of the whey protein. An additive law poorly defined selected RVA parameters. Both macromolecules interacted to define the viscosity of the mixture, and an exponential model predicted the viscosity better than the additive law. The results obtained in this study are discussed to assist the understanding of extrusion processing of starch-whey systems as models for whey-fortified snack and ready-to-eat foods.

Crystallization of spray-dried amorphous skim milk, lactose and lactose-salt mixtures at different relative humidities and storage times was studied by moisture sorption and X-ray diffraction tests. The results from the moisture sorption tests indicated that the time for 95% crystallization of skim milk powders at 75% and 89% relative humidities are 155 and 80 hours, respectively. For lactose, the 95% crystallization times at 51% and 75% relative humidities are 55 and 7 hours, respectively. A significant result is that salt delayed lactose crystallization, with lactose-salt mixtures (5:1 by weight) at 51% and 75% relative humidities having 95% crystallization times of 70 and 20 hours, respectively. Crystallization was also observed from increasing peak intensities in X-ray diffraction patterns. The rate of crystallization increased with increasing moisture content.

This paper proposes a fuzzy set approach that integrates objective and subjective information to evaluating kiwi wine quality. The 10 different kiwi wines experimentally were conducted firstly sensory evaluation. Then the contents of principal aroma components were identified and determined by the Headspace-Solid phase Microextraction-Gas Chromatography-Mass Spectrometry using quantitative standards with known amounts of target components and 3-Octanol as internal standards. The result of fuzzy set approach to assess and rank the kiwi wine quality showed KW-1 as the best kiwi wine. The results and outcomes of this study suggest that the approach described in this paper is more accurate and objective than conventional methods. It provides a comprehensive method for dealing with incomplete and imprecise information to support the whole evaluation process. This method should be utilized by the fruit wine industry around the world because of its practicability and superiority.

Lactobacillus acidophilus 1.1854 was used for CLA production in whole milk and alfalfa seed oil was used as substrate. Alfalfa seed oil contained linoleic acid about 40%. Results showed that alfalfa seed oil addition to the culture improved CLA production, indicating the presence of linoleic acid isomerase activity in the culture. The concentration of lactic acid bacteria, the incubation time, the substrate concentration, the pH, incubation temperature, the pre-incubation time and the substrate amount of pre-incubation were studied in our research and they are optimized at 2.5%(v/v), 21h, 0.05%(v/v), pH 6.4, 37°C, 11h and 10µL which brought the optimal conversion ratio at about 50%.

Many attempts to model the human gastrointestinal tract (GIT) were made since the beginning of the last decade. The main purpose was either to simulate an in vivo testing of drugs on animals or to investigate the viability of the probiotic intake. Two well-known physio-chemical models regarding the viability of the probiotics have been produced. In 1993, Molly et al. developed a simulator of the human intestinal microbial ecosystem (SHIME). Six reactors simulating the conditions of human stomach, duodenum/jejunum, ileum, caecum/ascending colon, transverse colon and descending colon were artificially developed. In 1995, Minekus et al. created a TNO gastro-intestinal model (TIM) with four computer-controlled chambers simulating the conditions of stomach, duodenum, jejunum and ileum. The simulated parameters included the body temperature, pH, salivary, gastric and intestinal mixing with peristaltic movements, secretions and absorption of water and small molecules. Despite the use of pharmacological, physiological and biochemical knowledge of the human and animal GIT and associated secretions, conflicting results such as the extremely low viability of probiotics were obtained. The failure of the above two models indicates the necessity of devising a suitable in vitro model that would be capable of simulating the digestion process as an exact replica of the actual in vivo model. In this paper, the key aspects of the above have been summarized and discussed.

With today's advancement in nanotechnology, Polymer-Clay Nanocomposite has emerged as a novel food packaging material due to its several benefits such as enhanced mechanical, thermal and barrier properties. This article discusses the potential use of these polymer composites as novel food packaging materials with emphasis on preparation, characterization, properties, recent developments and future prospects.