Loading...
Thesis
Browse
15 results
Search Results
ThesisItem Restricted OPTIMIZATION OF CONVECTIVE-CUM-MICROWAVE DEHYDRATION OF OYSTER MUSHROOMS (Pleurotus sajor-caju)(2013) Sakti BansalInvestigations were carried out to study the effect of drying parameters viz. loading density, air velocity, power level on convective-cum-microwave dehydration of oyster mushroom. Multi layer drying of commercially grown mushroom cv. Pleurotus sajor-caju was carried out at 3 levels of loading densities (26-52 kg/m2) and air velocities, 3-5 m/s and microwave drying was carried out at 3 power levels (270-810 W). The drying parameters studied were drying rate, temperature and relative humidity of outgoing air, product temperature and heat utilization factor. Quality attributes included rehydration ratio, shrinkage ratio, texture (hardness and chewiness), colour and overall acceptability. Multi layer drying of mushroom with an initial moisture content of 91% wb was carried out at 60°C in a mechanical drier till the moisture content reached 27% wb followed by drying in microwave oven to a final moisture content of 6.89% wb. It was observed that drying rate, relative humidity of outgoing air and heat utilization factor decreased with drying time but opposite trend was observed for temperature of outgoing air and product. The decline in drying rate increased with increase in air velocities and power level whereas opposite trend was observed for loading densities. Increase in loading density and air velocity resulted in decrease in heat utilization factor and relative humidity however temperature of outgoing air and product showed the opposite trend. Logarithmic model showed the highest adequacy of fit for multi layer drying and two term exponential model for microwave drying. The effective moisture diffusivity increased with increase in both loading density and air velocity. The increase in loading density resulted in increase in rehydration ratio, shrinkage ratio, colour change but decrease in texture and overall acceptability. The increase in air velocity resulted in increase in rehydration ratio, hardness, colour change overall acceptability but decrease in shrinkage ratio and chewiness. The increase in power level resulted in increase in rehydration ratio, texture, colour change and decrease in shrinkage ratio and overall acceptability. The optimum conditions for convective-cum-microwave drying of mushroom were found to be 38.80 kg/m2 loading density, 3.86 m/s air velocity and 413.6 W power level. Keywords: Oyster mushroom, drying kinetics, quality, optimizationThesisItem Open Access EFFECT OF ENZYMATIC TREATMENT ON OIL RECOVERY USING MECHANICAL EXPRESSION FROM MUSTARD SEEDS(PAU Ludhiana, 2011) Pawanpreet Singh Grewal; A.K. SinghThe experiments were carried out with the objectives to determine various engineering characteristics and determining the operational parameters for better recovery of oil from two varieties of Mustard seed i.e. PBR-91 and RLC-1. The experiments were designed using response surface methodology for making various combinations of moisture content (6, 9, 12, 15 and 18%w.b.), heating time (2,4,6, 8 and 10 min), heating temperature (40,60,80,100 and 120°C) and enzyme concentration (1, 2, 3, 4 and 5%) and the experiments were conducted using single chamber oil expeller. The quality of oil was determined using acid number and peroxide value. The effect of independent variables i.e. moisture content, enzyme concentration and heating temperature on oil yield and residual oil in cake of PBR-91 and RLC-1 variety were found significant however the effect of the heating time was found non-significant in both the varieties. The highest amount of oil yield is 32.30% at 9% moisture, 4% moisture content, 60°C heating temperature and 8 minute heating time for PBR-91 and 32.09% for RLC-1 at 9% moisture content, 60°C heating temperature and 8 minute heating time. There is 8% increase in the yield of the oil for PBR-91 extracted at optimum level of parameters whereas in RLC-1 there is 8.89% increase in the oil yield compared to untreated seeds. Flow behaviour of oil was studied at different temperatures ( 10, 20, 30, 40 and 50°C) and different moisture level (6, 9, 12, 15 and 18%) at constant shear rate 15 S-1 showed decreasing trend of viscosity with increase in temperature.The flow behaviour of the samples were predicted by the values of consistency coefficient and flow behavoiur index. The range for consistency of oil was found to be 1.32 to 90.12 (PBR-91) and1.13 to 65.12 (RLC-1) for Power law model where as in Casson model it was 4.14 to 24.2 (PBR-91) and 3.12 to 17.3 (RLC-1). The flow behaviour index of PBR-91 ranged from -0.68 to0.94 whereas it varied from 0.18 to 0.96 for RLC-1 in Power law model . The range of yield stress was found to be 4.37 to 432 (PBR-91) and 2.1 to 400.1 (RLC-1) for Casson model.ThesisItem Open Access EFFECT OF PACKAGING MATERIAL ON SHELF LIFE AND QUALITY OF GRAPES (Vitis vinifera L.)(PAU Ludhiana, 2011) Landge Kishor Changdeo; Jarnail SinghThe effect of packaging material on shelf life and quality of grapes cv. Thomson seedless was studied. Material was packed with three different packaging materials viz. Low density polyethylene (LDPE) of 100 guage, Polypropylene (PP) of 90 guage and Laminated aluminum foil (LAF). These samples were stored at 5˚C and 90- 95 % RH in the cold chamber. Control group of grapes samples were stored at room temperature without packaging. During the study viscoelastic behavior, PLW, moisture content, colour , TSS, Ascorbic acid content and Titrable acidity were measured at an interval of 5 days. The grapes stored at refrigerated conditions have shelf life of four weeks as compared to the control samples which has seven days. The LDPE film showed the best performance in terms of maintaining the hardness of fruit. The thickness of loading for packaging containers of grapes was calculated to be 45 cm for samples stored with LDPE. The PLW, variation in moisture content (% db), change in L, a, b colour values was observed to be minimum with LDPE. The quality parameters like Ascorbic acid content, Titrable acidity were least affected with the LAF packaging. The PP was the most effective packaging material for maintaining TSS values of fresh grapes. All the parameters PLW, colour, TSS, Ascorbic acid etc. were observed to be decreased at a faster rate in samples stored at atmospheric conditions in comparison with the samples stored at refrigerated conditions.ThesisItem Restricted MULTI-LAYER DRYING OF GINGER (Zingiber officinale(PAU Ludhiana, 2011) Tarun Garg; Satish KumarInvestigations were carried out to study the effect of drying parameters on multi-layer drying of ginger. The drying parameters studied were moisture content, drying rate, temperature and relative humidity of outgoing air, product temperature and heat utilization factor. Quality attributes included rehydration ratio, coefficient of rehydration, shrinkage ratio, volatile oil content, colour. The multi layer drying was carried out at 60°C in Satake mechanical drier till an average moisture content of 5-6 % was achieved. The total drying time was between 5-16.5 hours. It was observed that moisture content, drying rate, relative humidity of outgoing air and heat utilization factor decreased with drying time but opposite trend was observed for temperature of outgoing air and product. The decrease in moisture content increased with increase in air velocities whereas opposite trend was observed for loading densities. Drying rate was higher for higher air velocity but opposite for loading density. A maximum heat utilization factor was observed for high loading density and low air velocity. Increase in air velocity resulted in decrease in heat utilization factor and relative humidity however temperature of outgoing air and product showed the opposite trend. Similar effect was observed for loading density. At air velocity 3.11 m/s the drying rate was maximum (8.45% db/min) for loading density 27.99 kg/m2 and heat utilization factor was maximum (1.00) for loading density 87.01 kg/m2. The rehydration ratio and coefficient of rehydration were maximum for sample having low loading density and air velocity but shrinkage ratio and volatile oil content were minimum for combinations having high loading density and low air velocity. There was a significant change in colour of fresh and rehydrated samples. The optimum conditions for multi-layer drying of ginger were observed to be 44.66 kg/m2 loading density and 3.5 m/s air velocity and corresponding values of rehydration ratio, coefficient of rehydration, shrinkage ratio, volatile oil and colour change were 4.98, 0.64, 1.87, 1.15 and 5.72 respectively.ThesisItem Open Access PROCESS OPTIMIZATION FOR EXPRESSION OF OIL FROM DEHULLED SUNFLOWER (Helianthus annuus L.) SEEDS(PAU Ludhiana, 2013) Arul Selvam T; Tarsem ChandMechanical expression of oil from dehulled sunflower seed is highly desirable as it provides, at low cost, non-contaminated, nutritionally rich press cakes which can be processed into nutritious edible foods. Unfortunately, mechanical oil extraction process suffers from certain drawbacks. The dehulled sunflower seeds obstruct forward movement inside the expeller barrel due to the absence of hull portion and less friction. The main focus of the present study was to maximize the oil recovery and obtain nutritionally rich press cakes from dehulled sunflower seeds using mechanical oil expression. Physical and mechanical properties were studied under four different moisture content ranged from 6-18 % (d.b.). The results showed that the geometric mean diameter, surface area, volume, sphericity and aspect ratio, thousand seed/kernel weight, true density, porosity, the angle of repose, static coefficient of friction and rupture energy were found to be increasing linearly for seed and kernel. Whereas bulk density, initial cracking force and mean rupture force decreased linearly with the increase of moisture content for both seed and kernel under study. Pre treatments in the form of steaming and addition of bio-based friction materials such as rice bran and wheat bran at different levels were employed. Central composite rotatable design was used to generate a set of experiment at different pretreatment levels during oil expression. A statistical model predicted the maximum oil yield efficiency, maximum protein, minimum fibre, minimum residual oil, minimum chlorogenic acid, minimum free fatty acid and minimum peroxide value of dehulled sunflower oil and press cakes at these optimized variable conditions for rice bran incorporation: steaming time of 10 min, steaming pressure of 0.5 kg cm-2 and rice bran incorporation of 13.88g 100g-1 of dehulled sunflower seed. For wheat bran incorporation it was at steaming time of 15 min, steaming pressure of 1.00 kg cm-2 and wheat bran incorporation of 15g 100g-1 of dehulled sunflower seed. Using these variables results are validated under experimental condition in three independent replicates. Rice bran incorporated oil expression gave best results with high desirability value.ThesisItem Restricted SPRAY DRYING OF TOMATO JUICE(PAU Ludhiana, 2011) Wungshim Zimik; Mahesh KumarA study was conducted to produce tomato powder using spray dryer (LSD-48) in the food engineering laboratory. The rheological parameters of fresh tomato juice and reconstituted juice were evaluated with the help of CVO-100 rheometer in engineering properties laboratory. A full factorial central composite rotatable design was used. The variable selected were air inlet temperature (140-160oC), feed flow rate (2.1-4.1 ml/min) and maltodextrin concentration (22.5-32.5%). The responses used in the analysis includes: recovery, lycopene content, solubility and ascorbic acid content. The air inlet temperature (145oC), feed flow rate (2.6 ml/min) and maltodextrin concentration (27.5%) were found to be optimum. Experiments were also performed to find out the total soluble solids, hue angle, chroma, titrable acidity, packed bulk density and moisture content. Results shows that with increase in air inlet temperature and feed flow rate, the moisture content, lycopene, packed bulk density, ascorbic acid, titrable acidity and solubility time decreased. Colorimetric analyses showed that the hue angle and chroma values changed with the inlet temperatures. The flow characteristics studies of the tomato juice and reconstituted juice of the optimized spray dried powder was undertaken at different processing temperatures. The flow behaviour of the samples were studied at different temperature levels from 40°C to 60°C at an interval of 5°C and shear rate range of 10 to 100 s-1 with 60.5oBrix total soluble solids. The flow behaviour of the samples was predicted by the values of consistency coefficient and flow behaviour index. The range for consistency coefficient of the fresh juice and reconstituted juice was found to be from 5.93 Pa sn to 20 Pa sn for Power law model and 1.47 Pa sn to 9.81 Pa sn for Herschel-Bulkley model. The flow behaviour index of fresh juice and reconstituted juice was found to be in the range of 0.70 to 0.89 for Power law and between 0.70 to 0.90 for Herschel-Bulkley model. Sensory evaluation and overall acceptability was also conducted for the fresh tomato juice and reconstituted juice on a 9-point hedonic scale.ThesisItem Open Access Development of extruded snacks from potato chickpea blends(PAU Ludhiana, 2011) Rachna; Baljit SinghThe aim of the present study was to investigate the effects of feed moisture, barrel temperature and screw speed on product responses viz. specific mechanical energy (SME), bulk density (BD), water absorption index (WAI), water solubility index (WSI) and hardness using a response surface methodology. The blend of potato-rice and chickpea was extruded at different moisture content (14 -18%), screw speed (400 - 550 rpm) and barrel temperature (130 - 170°C). Feed moisture had significant effect on all product responses. Whereas screw speed and barrel temperature both independent variable had significant effect on SME, WSI and hardness of the product. Increase in feed moisture reduces SME and WSI and increases BD, WAI and hardness. Increase in screw speed decreases the bulk density (BD), water absorption index (WAI) and hardness of the snacks. Whereas increase in barrel temperature decreases the specific mechanical energy (SME), bulk density (BD), water absorption index (WAI) and hardness but increases the water solubility index (WSI). Optimized condition for preparation of snacks were 14% moisture, 550 rpm screw speed, 170°C temperature. The final product was having 12.04% protein, 2.79% fibre, 0.86% fat, 1.79% ash.ThesisItem Open Access EFFECT OF PACKAGING MATERIAL AND STORAGE CONDITIONS ON SHELF LIFE AND QUALITY OF DRIED GINGER(PAU Ludhiana, 2011) Jasmeen Kaur; Satish Kumar, GuptaThe study on the effect of packaging material and storage conditions on shelf life of dried ginger was undertaken to select the suitable package material for extending the shelf-life of dried ginger based on physico-chemical quality and sensory evaluation. The ginger was peeled, cut and dried into three physical forms i.e. dried ginger flakes, dried rhizome and ginger powder and packaged in HDPE films, laminated aluminium films, PET containers and glass containers. These dried and packaged samples were stored under ambient conditions and refrigerated temperature (3+0.5°C). The analysis was carried out to estimate the quality and shelf-life of the stored dried ginger during whole storage period of four months. The parameters evaluated were colour change in terms of L value, chroma & hue angle, volatile oil (%), flavor (hedonic scale), shrinkage/swelling, weight change (g) and moisture content (% wb). Weight change (g) and moisture content (% wb) increased whereas colour change in terms of L value, chroma, lightness, flavour and volatile oil were decreased during storage period. Shrinkage/Swelling remained almost same during the storage period. Based on these physic-chemical quality parameters and sensory evaluation, it was found that the best physical form was powder followed by flakes and rhizome. Glass containers was the best packaging material followed by laminated aluminium films, HDPE films and PET containers for extending the shelf-life and maintaining the quality of dried ginger upto 4 months. Refrigerated conditions were observed as the better storage conditions than the room temperature. The statistical analysis was also done to check the significance of different packaging materials used under different storage conditions.ThesisItem Open Access Drying Of Red Chillies (Capsicum Annum L.)And Its Subsequent Effect On Storage(Punjab Agricultural University; Ludhiana, 2005) Tarsem Chand; Jarnail Singh
