A. A. Patel

A comparative study of kinetic and connectionist modeling for shelf-life prediction of Basundi mix

A ready-to-reconstitute formulation of Basundi, a popular Indian dairy dessert was subjected to storage at various temperatures (10, 25 and 40xa0°C) and deteriorative changes in the Basundi mix were monitored using quality indices like pH, hydroxyl methyl furfural (HMF), bulk density (BD) and insolubility index (II). The multiple regression equations and the Arrhenius functions that describe the parameters’ dependence on temperature for the four physico-chemical parameters were integrated to develop mathematical models for predicting sensory quality of Basundi mix. Connectionist model using multilayer feed forward neural network with back propagation algorithm was also developed for predicting the storage life of the product employing artificial neural network (ANN) tool box of MATLAB software. The quality indices served as the input parameters whereas the output parameters were the sensorily evaluated flavour and total sensory score. A total of 140 observations were used and the prediction performance was judged on the basis of per cent root mean square error. The results obtained from the two approaches were compared. Relatively lower magnitudes of percent root mean square error for both the sensory parameters indicated that the connectionist models were better fitted than kinetic models for predicting storage life.

Storage related changes in ghee-based low-fat spread

In order to assess the shelf life of a low fat spread (LFS) based on ghee, the product with (PS) and without (CS) added 0.05 % (w/w) preservative potassium sorbate and packaged in 200xa0g polystyrene tubs was stored at 5xa0°C and evaluated for changes in sensory, physico-chemical and microbiological properties. On the basis of flavour score, the PS spread could be stored for 10xa0weeks without appreciable loss in quality as against the CS spread which could be stored only for 5xa0weeks. From the point of view of spreadability, body and texture and colour, the CS product was acceptable even after 11xa0weeks of storage. Use of preservative had an inhibitory effect on the development of free fatty acids (FFA) and thiobarbituric acid (TBA) reactive substances. While both the products showed an increasing tendency to whey off during storage, CS wheyed off more than PS. The two spreads showed similar oiling off, which increased slightly during the storage. Microbiologically, the ghee-based low fat spreads with and without preservative was stable for 9 and 3xa0weeks, respectively, from the view point of yeast and mould growth; but the preservative had little effect on the total viable count. Coliforms were absent in all the samples in fresh and during storage.

Determination of relationship between sensory viscosity rating and instrumental flow behaviour of soluble dietary fibers

The shear-thinning low, medium and high-viscosity fiber preparations (0.15–1.05xa0% psyllium husk, 0.07–0.6xa0% guar gum, 0.15–1.20xa0% gum tragacanth, 0.1–0.8xa0% gum karaya, 0.15–1.05xa0% high-viscosity Carboxy Methyl Cellulose and 0.1–0.7xa0% xanthan gum) showed that the consistency coefficient (k) was a function of concentration, the relationship being exponential (R2, 0.87–0.96; Pxa0<xa00.01). The flow behaviour index (n) (except for gum karaya and CMC) was exponentially related to concentration (R2, 0.61–0.98). The relationship between k and sensory viscosity rating (SVR) was essentially linear in nearly all cases. The SVR could be predicted from the consistency coefficient using the regression equations developed. Also, the relationship of k with fiber concentration would make it possible to identify the concentration of a particular gum required to have desired consistency in terms of SVR.

Heat penetration characteristics and physico-chemical properties of in-pouch processed dairy dessert (kheer)

Kheer, a traditional milk product of South East Asia, containing cooked rice grains in a creamy sweetened concentrated milk, has no large-scale production due to its poor shelf life. Shelf-life was improved by development of a process based on in-pouch thermal processing employing a rotary retort. Product development included optimization of rice-to-milk solids ratio (0.18–0.52) and total milk solids levels (16–26xa0%) to simulate the conventional product in taste, appearance and textural attributes. Various Fo values (12.4–14.8) were examined with regard to product quality. While the TBA value tended to increase (0.073–0.081) the reflectance value (35.3–43.4) declined with increasing Fo. The pH of the product (6.04–6.10) showed a slight tendency to increase with Fo. Sensorily, the product was found to be acceptable for a period of 150xa0days at 37xa0°C.

Effect of fiber blends, total solids, heat treatment, whey protein concentrate and stage of sugar incorporation on dietary fiber-fortified Kheer

Owing to the proven beneficial role of dietary fiber (DF) on human health, feasibility of incorporating commercially available soluble and insoluble DF preparations into rice-milk-pudding (kheer, a popular Indian delicacy) was studied through process modification. The novel approach of preparing reduced fat DF-fortified-kheer (DFFK) by developing liquid/cream phase and particulate/rice phase separately, and subsequently blending the two was developed. The major processing variables studied were total solids (TS) in the liquid phase, type of fiber blend, flavor-simulation through heat treatment or added whey protein, and the presence of sugar in water for pre-cooking of rice. Reduced fat DFFK made from three different pre-standardized fiber blends was quite acceptable to the sensory panel (overall rating 7.5). With increasing TS in milk up to 16.5%, sensory acceptability of DFFK increased. There was a small but perceivable improvement in the flavour of DFFK when precooking of rice was carried out in sweetened water. Reduced fat DFFK from different fiber blends was found to be reasonably close to conventional kheer. DFFK prepared from Blend-I provided 3.31xa0g dietary fiber/100xa0kcal (suitable for the claim “High-in-Fiber”) with 38.71% Reduced-Fat. With the developed process of fortification of kheer with DF, it is possible to reduce fat (and thus calories) to cater to the needs of consumers seeking good health.