Quality changes in cocoyam flours during storage
Abstract Cocoyam tubers were subjected to two processing methods (fermentation and parboiling) and milled into flour. The samples were stored at 25°C, 35°C, and 45°C and analyzed at 2 weeks interval for 8 weeks for their nutritional, functional, and pasting properties. Data obtained were subjected to multiple analysis of variance. Storage period and its interactive effect with the processing methods had significant (P < 0.05) effects on all the nutritional composition of the flour except for the fat content. Water absorption index, wettability, and bulk density ranged from 1.94–2.72%, 25.30–135.50 sec, and 0.48–0.71 g/cm3, respectively. The entire pasting properties were significantly affected by the storage period while the interaction between storage temperature, processing methods, and storage period affected all the pasting properties except the peak time, peak, and breakdown viscosity. This study showed that processing methods storage periods and storage temperatures produced cocoyam flour with different quality characteristics.
Chickpea flour supplemented high protein composite formulation for flatbreads: Effect of packaging materials and storage temperature on the ready mix
Abstract Shelf life studies are gaining impetus due to the consumer’s attentiveness towards excellence of the packaged products. The present study was carried out to develop a composite premix formulation for chickpea supplemented flatbread and to estimate the suitability of packaging material and storage temperature on its quality. Whole wheat flour was supplemented with chickpea flour from 10 to 50%; fenugreek powder and onion flakes at 0–20%; salt, ginger powder, green chilli powder and red chilli powder at 0–2%, mango powder at 0–5%; glycerol mono stearate (GMS) and sodium steaoryl-2-lactylate (SSL) at 0–0.50% and fat at 0–4%. Two formulations (I and II) were prepared after selecting the appropriate levels of ingredients by sensory evaluation using trial and error method. Formulations were packed in zip pouch, aluminum laminate and high density poly ethylene at room and refrigeration temperatures. Changes in the total composition, water activity, free fatty acid, overall acceptability and texture of flatbreads were assessed for four months. Storage period had most significant effect followed by storage temperature and packaging material on quality attributes of formulations. All the samples were in acceptable condition where aluminum laminate and refrigerated temperature were the best combination for storage of formulation I and II.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.