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2008 - 20093
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Subject: Food Science and Technology × End date: 2009 × Start date: 2007 ×
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    ThesisItemOpen Access
    Screening of mango varieties for preparation of ready-to-serve beverage
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2009-08) Phool Chand; Chopra, C.S.
    The present study pertaining to evaluation of different cultivars of mango for preparation of ready-to-serve beverage (RTS) was conducted in the Department of Food Science & Technology, G.B. Pant University of Agriculture and Technology, Pantnagar, U.S. Nagar (Uttarakhand) during the year 2008-09. The cultivars differed significantly in terms of fruit weight (110.0-574.5g), length (7.18-14.59 cm), breadth (5.23-9.07 cm), specific gravity (0.953-1.061) and content of flesh (58.18-79.90%), peels (9.10-22.52%) and stone (11.05-20.55%). Variations in pH (3.75-4.49) and content of TSS (11.5-17.33%), moisture (76.32-88.65%), acidity as citric acid (0.16-0.31%), vitamin C (15.30-107.27 mg/100g), ash (0.24-0.43%); reducing, non reducing and total sugars (3.08-4.64, 8.91-15.71 and 12.52-20.36%) in flesh were statistically significant, Fazli recorded highest fruit weight, length and breadth while these were minimum with Alphanso. Fazli having maximum flesh also had highest acidity while Pant Sindoori and Dashehari recorded minimum flesh and acidity, respectively. Langra flesh was found to be the richest source of vitamin C. Dashehari, Langra and Chausa varieties were selected for making RTS of composition 10% pulp, 10% TSS and 0.30% acidity, on the basis of their highest overall acceptability score (8.67, 7.89 and 7.33, respectively). The sulfited and in-bottle pasteurized drinks prepared from these selected cultivars had >6 months of shelf-life at ambient conditions.
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    ThesisItemOpen Access
    Optimization of enzymic extraction process for guava juice and to study its storage stability
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-01) Ahmad, Iqrar; Jha, Yogesh Kumar
    Guava fruits (cv. Pant prabhat) as used in present study had 131.0g average fruit weight, 5.8 cm polar diameter and 6.3 cm transverse diameter, 87.24 % flesh and 3.34 % seed and its flesh contained 84.57% moisture, 10.67 (°B) TSS and 0.72% total mineral, 3.73% reducing sugars, 2.50% non reducing sugars and 6.37% total sugars, 0.33% acidity (as citric acid), 4.43 pH and 175.96 mg/100g ascorbic acid. Pectin, cellulose and Hemicellulose content of guava flesh were found to be 1.27% (as calcium pectate), 2.26% and 3.67%, respectively. Hot pulping process with 10 minutes of heating time was selected to obtain the pulp for further processing into juice. Guava pulp treated with enzyme pectinase 0.1 to 0.3% (w/w), cellulase 0.05 to 0.25% (w/w) and hemicellulase 0.05 to 0.25% (w/w) was incubated at 50°C for 6-10 hours. A 4-factor, 5-level central composite rotatable design with 7 experiments at central point was chosen to carry out the studies. The independent variables were the concentration of pectinase (X1), cellulase (X2), hemicellulase (X3) and time of incubation (X4). The response functions were juice yield, TSS, juice clarity, viscosity, acidity, ascorbic acid and Overall acceptability. The models used to predict the effect of variables (Pectinase, cellulase, hemicellulase and time of incubation) on all the responses were found to be adequate. It showed that treatment of pulp with 0.245 per cent pectinase, 0.135 per cent cellulase, and 0.130 per cent hemicellulase for 9.25 hours at 50°C were the optimum conditions for the production of clear guava juice. Guava pulp when treated under these conditions yielded 85.25% juice of 9.57 °Brix TSS, 93.96% clarity, 1.458 relative viscosity, 0.426% acidity, 61.73 mg/100g ascorbic acid and 7.4 overall acceptability. The predicted values corresponding to the optimized conditions were: juice yield 85.25%, TSS 9.57 °Brix, juice clarity 93.96%, relative viscosity 1.458, acidity 0.426%, ascorbic acid 61.73 mg/100g and overall acceptability 7.42. Yield, clarity and viscosity of juice obtained by conventional process were 19.7-22.2%, 20.6-33.3% and 2.470-1.923, respectively. The optimized conditions yielded a juice of better sensory score for colour (8.0), taste (7.5), aroma (7.5), body/viscosity (7.3) and higher overall acceptability (7.6) as compared to the corresponding values of 7.2, 7.3, 7.4, 7.6 and 7.8 for unclarified juice. No significant changes in sensory attributes were observed throughout the entire period of 60 days at both the temperatures. TSS content of guava juice remains unchanged upto 60 days of storage at 25 and 45 0C whereas, a non significant increase in acidity and decrease in pH of the guava juice (3.95-3.78) was recorded at both the temperatures. The effect of storage period on the ascorbic acid content and non-enzymatic browning was found to be significant (P≤0.01). There was significant (P≤0.1) decrease in juice clarity at both the temperatures of storage. Viscosity of the guava juice was decreased non significantly (P≤0.01). After 30 days of storage a significant (P≤0.01) increase in Total plate and Yeast and mold count was reported at both the temperatures of storage. Coliforms were, not detected at all in any of the stored samples during the 60 days of storage.
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    ThesisItemOpen Access
    Preparation of shatavari (Asparagus racemosus) powder and its utilization as a preservative and therapeutic agent in burfi
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-05) Saini, Pinki; Tyagi, S.M.
    The present investigation was conducted to optimize the process of preparation of A. racemosus (shatavari) root powder. Response Surface Methodology (RSM) was employed to select optimum levels of various variables on the basis of maximum retention of saponins in shatavari powder. The effect of addition of shatavari root powder as a preservative on the quality of burfi was also studied. Storage studies were conducted to assess the shelf life of burfi at room temperature and refrigeration temperatures. The shatavari roots have average moisture, protein, fat, carbohydrates, ash and fibre as 88.30, 3.06, 0.2, 5.58, 0.46 and 2.4 per cent, respectively. The copper, manganese, potassium, sodium, calcium, iron, cobalt, zinc and magnesium content of fresh shatavari root were 0.11±0.05, 1.0±0.08, 12.27±0.12, 4.82±0.11, 18.09±0.43, 10.17±0.32, 0.11±0.09, 0.17±0.04 and 113.10±0.54 mg/100g, respectively. The ascorbic acid, thiamine and riboflavin content of shatavari roots were 8.95±0.11, 0.20±0.08 and 0.71±0.03 μg/g, respectively. The saponin content of fresh shatavari roots was 85.73±0.18 mg/100g. The maximum saponin content was retained by chemical blanching of 1.5 cm thick roots using 100ppm potassium metabisulphite at 40oC for 2 min. The roots were dried in hot air cabinet drier at a temperature of 60oC for 11 hours for preparation of powder. The shatavari root powder has average moisture, protein, fat, carbohydrates, ash and fibre as 6.6, 21.8, 3.76, 48.54, 4.5 and 14.8 per cent, respectively. The copper, manganese, potassium, sodium, calcium, iron, cobalt, zinc and magnesium content of shatavari root powder were 0.51±0.06, 3.35±0.18, 14.91±0.33, 10.95±0.21, 80.93±0.37, 24.22±0.56, 0.39±0.05, 1.01±0.03 and 258.10±0.55 mg/100g, respectively. The ascorbic acid, thiamine and riboflavin content of shatavari root powder were 4.48±0.06, 0.16±0.06 and 0.34±0.43 μg/g, respectively. The saponin content of shatavari root powder was 84.12±0.74 mg/100g. Burfi was prepared in the laboratory from 7.2 per cent fat buffalo milk. The milk was heated and stirred continuously to prepare dessicated milk/ khoa. Ground sugar was added @ 30 per cent (w/w) in khoa followed by addition of 1.0 per cent (w/w) shatavari root powder as a preservative. Average moisture, fat, protein, lactose, sucrose and ash in burfi sample with 1.0 per cent shatavari root powder were 17.21, 14.54, 30.12, 16.54, 18.31 and 3.37 per cent, respectively. Copper, manganese, potassium, calcium, iron, zinc and magnesium content of shatavari incorporated burfi were 0.41±0.07, 1.54±0.25, 18.42±0.53, 86.0±0.58, 34.90±0.41, 3.18±0.24 and 9.96±0.13 mg/100g, respectively. The saponin content in 1 per cent shatavari root powder incorporated burfi was observed to 0.80±0.07 mg/100g. The samples of burfi could be stored satisfactorily for 21 days at room temperature (30+1oC) and for 28 days at refrigeration temperature (7+1oC).