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20133
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Subject: Food Science and Technology × End date: 2013 × Start date: 2013 × Type: Thesis ×
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    Processing of selected varieties of Punjab Potato (Solanum tuberosum) to produce flakes and flour using hot air drying
    (PAU Ludhiana, 2013) Shweta Goyal; Mahesh Kumar
    Investigation were carried out to produce flakes and flour from potatoes. Two popular variety of potatoes in the state of Punjab namely Kufri Pukhraj and Kufri Jyoti were selected for this purpose. The raw potatoes procured from the local vegetable market were peeled, boiled in a microwave. A mash was produced by crushing boiled potatoes followed by dipping in 0.2%KMS solution for 1 hour to remove the sugars. The drained mashed potatoes were dried at 50°C, 60°C & 70°C in the layers of 5, 6 & 7 mm. The prepared mash was also dried in a solar dryer. It consumed about 900-1290 min to dry at 50°C & 70°C. Effective moisture diffusivity varied between 1.43x10-10 & 3.98 x 10-10 m2/sec for tray dried sample in comparison to 2.79 x 10-10 to 4.39x10-10 m2/s for solar dried. The prepared flakes were grounded to produce the flour that was stored in HDPE and LDPE pouches, Al laminate & glass bottles and kept at room temperature. The parameters like moisture content, colour, NEB, flavor etc. were estimated at regular interval of 15 days. The process parameters, temperature & thickness were optimized by RSM technique for the responses, namely rehydration ratio (RR), shrinkage ratio (SR), reducing sugar, swelling index (SI), starch content, colour (L value) and overall acceptability (OA). The vital values of these parameters were 1.83-2.8 (RR), 0.76-1.2 (SR), 0.012-0.189 (reducing sugar), 1.52-2.14 (SI), 5.82-6.45 (starch content), 47.4-53.12 (L value) and 7.06-7.52 (OA) respectively. The optimized values of temperature & thickness lie in the range of 61.27-58.44°C & 6.56-5.86 mm respectively for tray & solar dried, Kufri pukhraj & jyoti potato. From the study, it was concluded that the log model showed high adequacy of fit & best result was obtained for laminate packed potato flour.
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    ThesisItemOpen Access
    STUDIES ON DRYING BEHAVIOUR AND QUALITY OF GARLIC (Allium sativum L.) USING HYBRID DRYING TECHNIQUES
    (PAU Ludhiana, 2013) Jaspreet Singh Grewal; M. S., Alam
    Investigations were carried out to study the drying kinetics of garlic slices i.e 3mm size for selected hybrid drying techniques, convective-cum-microwave (CCM) and fluidized-cum-microwave (FCM). The experiments were conducted using completely randomized design (CRD) by varying drying parameters viz. KMS concentration (0.1-0.5 %), drying air temperature (55-75°C) and microwave power level (810-1350 W). The garlic slices were dried to 63(±1) % d.b moisture content by convective tray drying/fluidized bed drying and further dried up to 6(+1) % d.b by microwave drying. Five empirical models were fitted to the kinetics data of convective, fluidized and microwave drying and their adequacy of fit was investigated. Response surface methodology (RSM) was employed for optimization of drying process parameters for CCM and FCM drying using 3-factor Box-Wilson design. Optimization was done on the basis of minimum drying time, specific energy consumption, shrinkage ratio, texture (hardness), non enzymatic browning, maximum rehydration ratio, colour (L-value) and overall acceptability. Dried garlic flakes developed under optimized drying process conditions for both the hybrid drying techniques were packed in three packaging material (Aluminum, LDPE and HDPE bags) and stored under ambient condition (220C to 320C temperature, 45 to 55 % RH). In order to develop garlic flakes, the total drying time varied from 115 to 187.17 and 48 to 72.17 min for CCM and FCM drying respectively. The average effective diffusivity increased with increase in drying air temperature and power level. Among various models checked for their adequacy of fit to the experimental data of drying, the Two term exponential model for convective tray drying, logarithmic model for both fluidized bed and microwave drying were found to be the best fitted model representing the drying kinetics. The optimized drying process parameters obtained were: 0.5 % KMS concentration, 59.41ºC temperature and 810 W power level; 0.1 % KMS concentration, 63.92ºC temperature and 810 W power level for CCM and FCM drying respectively. The dried garlic flakes packed in Aluminum packs was adjudged to be the during three months storage period
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    ThesisItemOpen Access
    OPTIMIZATION OF MODIFIED ATMOSPHERE PACKAGING FOR CUCUMBER (Cucumis sativus L.)
    (PAU Ludhiana, 2013) Kandale Pallavi Uttamkumar; Preetinder Kaur
    The present study was undertaken to optimize Modified Atmosphere Packaging (MAP) for cucumber (Cucumis sativus L.) to obtain the maximum shelf life on the basis of quality attributes and sensory evaluation during the storage study experiment. Respiration and transpiration rates of cucumber at different temperatures viz. 5, 10, 15°C and ambient (18.6°C) were determined. The respiration rate was described assuming the combined type of inhibition in the enzyme kinetics model. Arrhenius relationship was used to explain the temperature dependence of respiration rate, respiratory quotient and transpiration rate of fresh cucumber. A theoretical analysis for design of MAP for selection of appropriate packaging film was carried out by matching the data obtained in respiration study with the permeabilities of commercially available packaging films. Cucumber was packed in LDPE and stored under different conditions such as film thickness: 100, 150, 200 gauge; package fill weight = 200, 300, 400g; level of perforations: 0, 2, 4; storage temperature: 5, 10, 15°C. The qualitative analysis of cucumber throughout the storage study was done in terms physiological loss in weight, total colour difference, firmness, total chlorophyll, and ascorbic acid. Sensory evaluation was done on the basis of visual appearance, odour rating and water accumulation. The study also revealed that the low temperature storage better retained the quality and quantity of fresh cucumber during its storage. MAP along with low temperature storage helped in enhancing shelf life of fresh cucumber upto 28 days. The optimized conditions obtained for shelf life extension of cucumber under MAP by using response surface methodology was temperature: 6.10°C, film thickness: 135.01 gauge, fill weight: 274.61 g, perforations: 0 and the expected shelf life of fresh cucumber at optimized conditions was 21 days.