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20173
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Subject: Food Science and Technology × End date: 2017 × Start date: 2017 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Development of instant vegetable soup mixes using extrusion technology
    (Punjab Agricultural University, Ludhiana, 2017) Gandhi, Neeraj; Baljit Singh
    The present investigation was undertaken to explore the possibility of using extrusion technology for development of Instant Vegetable Soup Mixes. Corn and potato starches were processed using co- rotating twin screw extruder at varying processing conditions as per the experimental design. Response surface methodology was used for optimization of the extrusion processing conditions and regression analysis was carried out to fit mathematical models to the experimental data. Feed moisture (14-18%), barrel temperature (125-175°C), screw speed (400-550 rpm) were chosen as the independent variables while specific mechanical energy (SME), bulk density (BD), expansion ratio (ER), water absorption index (WAI), water solubility index (WSI), degree of gelatinisation (DG), in-vitro starch digestibility (SD), colour and viscosity were the product responses. All the processing conditions had significant influence on the extruded starches. Optimization results indicated that feed moisture of 17 and 18%, screw speed of 414 and 533 rpm and barrel temperature of 131 and 135°C would produce extruded corn and potato starches respectively of preferable functional properties as required for preparation of instant soup mixes. Instant Vegetable Soup Mixes were prepared by uniform blending of recommended levels of extruded corn and potato starches with other ingredients based on the sensory evaluation. Instant Vegetable Soup Mix contained extruded corn/ potato starch 50%, dried tomato/ mushroom powder 17.9%, skim milk powder 10%, sugar 10%, salt 10%, black pepper 2% and citric acid 0.1% (w/w). Reasonably higher degree of gelatinization and starch digestibility was achieved in the final product. The developed soup mix contains high protein, less fat and ash content with low cost when compared with the commercially available similar products. The product packed in aluminium laminates and stored at ambient storage conditions were found more stable and acceptable than packed in polyethylene for 6 months storage period.
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    ThesisItemOpen Access
    Biological Activation of Grains: Characterization, Functionality and Utilization
    (Punjab Agricultural University, Ludhiana, 2017) Arashdeep Singh; Sharma, Savita
    The present investigation was undertaken to study the biological activation of grains (Brown rice (PR 123), Sorghum (SL 44), Wheat (HD 2967), Pigeon pea (AL 201) and Barley (PL 426))for their characterization, functionality and utilization. Grains after steeping were subjected to biological activation for 12, 24, 36 and 48 h at 25, 30 and 35 oC. Steeping increased the moisture results in better germination capacity of grains. Physical characteristics as well as crude protein, fat, ash and fibre content of the grains of the grain were inversely affected by activation conditions. Biological activation increased the diastase enzyme activity and also activates the hydrolytic enzymes that act on starch and reducing its concentration and resulting in more sugars. Significant (p<0.05) decrease in the bulk density, water absorption capacity and swelling power of flour prepared from activated grains was observed due to enzymatic modification of starch. Gel consistency and oil absorption capacity of flour increase significantly (p<0.05) as the grain activation time increased from 12-48 h and temperature from 25 to 35 oC. Raw flour had lowest emulsion activity and stability as well as foaming capacity and stability, while increase in biological activation conditions significantly (p<0.05) enhanced the emulsifying and foaming properties of flour. Paste clarity of native flour was highest among all the samples which after grain activation were significantly reduced; however, biological activation increased the % syneresis due to enzymatic thinning of starch. Proteins were modified by action of enzymes during higher biological activation time and temperature conditions, which also results higher protein solubility. Least gelation concentration (LGC) increased as grain activation conditions progressed and highest LGC was observed after 48 h of grain activation at 35 oC. Increase in biological activation conditions enhanced the in vitro digestibility of starch and protein. Biological activation of grains for longer time period at higher temperature significantly increased the antioxidant activity, total phenolic and total flavonoid content. Similarly reducing power and metal chelating activity also enhanced as grain activation time increased from 12 to 48 h and temperature from 25 to 35 oC. Increased enzymatic activity during biological activation degrades the starch and thus lowers down the peak and final viscosity of grains and also lowers down the Lightness value of the grains. Biologically activated grains packed in high density polyethylene and stored at room temperature for up to 4 months showed considerable stability during their storage. Biologically activated grain were utilized at varying levels in pasta, cookies, flat bread and chapatti and the overall acceptability results showed that they were successfully utilized as functional ingredient at 10 to 15% levels in different products.
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    ThesisItemOpen Access
    Development of synbiotic drinks from finger millet and oats
    (Punjab Agricultural University, Ludhiana, 2017) Ashwani Kumar; Amarjeet Kaur
    The food habits have been changing throughout world and there is an increase in the demand of energy dense, nutrient rich, vegan, and wholesome foods with specific health benefits. Composite foods are trending due to their richness in nutrients and probiotics are preferred for their specific health benefits. Therefore, present work was carried out to develop a composite drink using finger millet (VL Manduaa 315), oats (Kent & Quaker brand oats) and double toned milk. All the raw materials were assessed for proximate composition. The effect of germination on finger millet was studied at 25° C for time intervals ranging from 0 to 96 hours for changes in functional properties, nutritional and anti-nutritional contents. Based on these changes, 84 hours/25 °C germination time was selected as best germination time and was used to carry out further studies. The process for the preparation of malt drink was standardized. Malt drink prepared with 60:40 of finger millet malt to oats with three times of water was selected best on basis of sensory acceptability. Response surface methodology (RSM) was used for the selection of malt drink and double toned milk for preparation of composite drink. On the bases of responses generated by software, 47:53 of malt drink to double toned milk was selected as best combination for the preparation of composite drink. To further enhance its nutritional and functional values, composite drink was flavoured with rose syrup and marigold powder. The prepared composite drink was high in total solids (22 percent), carbohydrates (16 percent), minerals (1.02 percent) and energy content (83 Kcal/100ml). It was low in fat (1.02%), cholesterol (2.67 mg/100 ml) and lactose (1.26 g/100ml) as compared to dairy milk. It also contained the good amount of health promoting components like, soluble dietary fibre (1.30 g/100 ml), beta-glucan (112 mg/ 100 ml) and anthocyanins (2.81 mg/100 ml) which are otherwise absent in dairy milk. The presence of dietary fibre made it good prebiotic and its application as a substrate for the growth of Lactobacillus bacteria viz. L. acidophilus, L. rhamnosus and L. casei revealed that the growth was higher in comparison to dairy milk. Storage studies further strengthen its claim to be used as a carrier for probiotic bacteria as it was capable to support bacterial life for more time as compared to dairy milk. The synbiotic drink prepared with L. acidophilus had best sensory characteristics and scored an average sensory score of 87.71 out of 100 on a composite sensory scale. Both, the products i.e. composite and synbiotic drinks required refrigerated storage and had a storage life of 60 days and 20 days, respectively at 4±2° C. The product is recommended as a health drink because it was rich in nutrients and had live probiotic bacteria in adequate amounts.