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ThesisItem Open Access Development and Evaluation of Refraction Based System for Dehydration of Potato(Punjab Agricultural University, Ludhiana, 2018) Zalpouri, Ruchika; Preetinder KaurThe present study was conducted to develop and evaluate a refraction based system for dehydration of potato. Refraction based drying system was developed in Pilot plant, Department of Processing and Food Engineering, Punjab Agricultural University. The potatoes were peeled, cut into quarters, hot water blanched and immersed in 0.2% KMS solution for 15 min. After pretreatment, the potatoes were processed into puree and a known amount of distilled water was added to the puree to achieve desired TSS levels. The potato puree was dried by different drying methods viz. convective tray drying and refraction based drying system. The drying experiments were carried out at different TSS (8, 10 and 12º Brix), different blanching time (3, 4 and 5min) and at varying drying temperature 50, 60 and 70°C in convective tray drying and 70, 80 and 90oC in the refraction based drying system. It was observed that the physical properties of potato flakes were significantly affected by blanching time (p< 0.05). The moisture content ranged from 6.16-1.57% (db) and 7.61-3.46% (db) of potato flakes dried in refraction based drying system and convective tray dryer. Color values varied significantly (p<0.05) with respect to the drying method. Response Surface Methodology was used for optimization of process parameters. For refraction based drying system, the optimum operating conditions for drying temperature, blanching time and TSS were 70.00°C, 5.00 min and 11.54°Brix. At optimum condition, the values of responses were as follows protein content (31.66 mg/g), starch content (144.04 mg/g), reducing sugars (0.75 mg/g) and total sugars (6.25 mg/g) of dried potato flakes. For convective tray drying, optimum operating conditions for drying temperature, blanching time and TSS were 50.00°C, 4.23 min and 12.00°Brix. At optimum condition, the values of responses were as follows protein content (19.40 mg/g), starch content (16.47 mg/g), reducing sugars (0.94 mg/g) and total sugars (6.41 mg/g) of dried potato flakes. After considering all the parameters, it was found that refraction based drying system was more efficient as compared to the convective tray dryer.ThesisItem Open Access Development and evaluation of energy efficient tunnel dryer for chilli(Punjab Agricultural University, Ludhiana, 2018) Harmanpreet Kaur; Sharma, S.R.The study was conducted to develop and evaluate an energy efficient solar tunnel dryer. The dryer had dimensions of 12 X 8 X 4 m made of galvanized steel pipes and covered with 200µ thick polyethylene sheet having anti-mist and anti-drip properties. Three turbine fans were installed at the roof top of the dryer to provide natural ventilation. The performance evaluation of developed dryer was done for drying red chillies (CH-27). The maximum temperature recorded inside the dryer was 78°C which was 60.2 % higher than the corresponding ambient air temperature of 47°C. The corresponding relative humidity was 9.6 % against ambient air relative humidity of 21 %. The drying behaviour of pretreated red chillies was studied and colour of dried chilli was measured. The final moisture content ranged from 2.07% (d.b.) to 8.54% (d.b). In solar tunnel drying technique, the maximum drying time was found to be 31 sunshine hours for control whole chillies against 45 sunshine hours in open sun drying whereas the minimum drying time was found to be 12 sunshine hours for chemically treated chopped chillies against 15 sunshine hours in open sun drying. Also quality of chilli powder after grinding dried chillies was determined in terms of colour, colouring matter, capsaicin content and oleoresin content. Solar tunnel drying technique was much better than open sun drying technique in terms of drying behaviour and quality parameters. Solar tunnel dryer was found to be economical with pay-back period of 2.5 months and cost-benefit ratio greater than 1.ThesisItem Restricted Modeling and optimization of extrusion process for utilization of vegetable waste(Punjab Agricultural University, Ludhiana, 2018) Choudhary, Kanupriya; Alam, M.S.Investigations were carried out to determine the best blanching pre-treatment and drying method for the development of dried radish leaves and pea pods (vegetable waste; VW) powder. The experiments were conducted using completely randomized design (CRD) by varying the blanching pre-treatments viz. hot water (HB), potassium metabisulphate (KMS), citric acid (CB) and drying methods viz. sun drying , solar drying and convective drying ( 55, 65 and 75°C). All the results were statistically analysed to estimate the significant difference between blanching pre-treatments and drying methods on the basis of physico-chemical quality attributes namely drying time, equilibrium moisture content, amino acid content, lignin content, crude fibre, color change and overall acceptability. The best quality dried vegetable waste powder was utilized in development of vegetable waste incorporated soy-cereal based product. Rice based extruded product were developed by replacing the base material (rice) with vegetable waste (VW)-soy powder (SP) mixed in equal proportion. The vegetable waste i.e. Radish leaves and pea pods powder mixed in equal proportion. Response surface methodology (RSM) was employed for optimization of extrusion process using four factor, three level Box-Behnken design. The extrusion process parameters i.e. VW-SP proportion (%), feed moisture content (% wb), die temperature (°C) and screw speed (rpm) for rice based extrudates were optimized for the responses namely bulk density (BD), specific mechanical energy (SME), expansion ratio (ER), water absorption index (WAI), water solubility index (WSI), protein content (PC), crude fibre (CF), hardness (H), color change (CC) and overall acceptability (OA). In addition to the optimization of extrusion process the modeling of extrusion process variables by using RSM and genetic algorithms (GAs) was done. The developed models were fitted to the extrusion data and their adequacy of fit was investigated. The hot water blanched radish leaves, convectively dried at 65°C was found to be best for utilization in the extruded product. The untreated samples (UT) of pea pods dried convectively at 75°C was found to be best for utilization in the extruded product. For rice based extrudates the optimum values of process parameters obtained by using RSM were: 35% VW-SP (i.e. 65% rice proportion) with 13.17% feed moisture content, 152.29°C die temperature and 360.42 rpm screw speed. Results obtained from RSM and GA were comparable. The vegetable waste and defatted soy flour can be successfully incorporated @ 35% i.e. 17.5% vegetable waste i.e. 8.75% radish leaves powder, 8.75% pea pods powder and 17.5% defatted soy flour powder.ThesisItem Restricted Enhancement of shelf life of Capsicum using ozone(Punjab Agricultural University, Ludhiana, 2017) Ummat, Viruja; Singh, A.KThe present study was conducted with an objective to study the effect of a strong oxidizing agent known as ozone, on shelf life enhancement of fresh cut capsicum shreds, which were later stored in different storage conditions. Green capsicum also known as bell peppers were cut into 6-7 mm shreds and treated with aqueous ozone dosages 1, 1.4, 2, 2.4 and 3 mg/l for 1, 3 and 5 minutes. Shreds dipped in tap water for 3 minutes were taken as control. The samples were packed in polypropylene packages and stored in refrigerated (5±0.5°C, RH 85±5%) and ambient conditions (33±2°C, RH 19±2%). The effect of ozone dosages and treatment durations on the shelf life enhancement of shreds and on various physicochemical and biological quality attributes was studied. Ozone showed a positive result in enhancing the shelf life by reducing microbial load, without having any adverse effect on the quality parameters. The higher dosages showed slight decrease in the ascorbic acid content, however these reductions were found to be insignificant. The samples stored in refrigerated conditions had more shelf life than the samples stored in the ambient conditions. The samples stored in the ambient conditions lasted only for a day due to the temperature condition. The shelf life of capsicum shreds stored at refrigerated conditions was found as 14 days when treated with 2.4 mg/l ozone for 5 min, as compared to shelf life of 8 days for control samples, considering various quality indices. These conditions gave the best results.ThesisItem Restricted Design, development and performance evaluation of solar assisted mechanical tray dryer for chillies(Punjab Agricultural University, Ludhiana, 2017) Arora, Sakshi; Mittal, T.C.The present study was conducted with an objective to design and develop a solar assisted mechanical tray dryer to dry red chillies that uses solar energy during sunshine hours and backup energy during non-sunshine hours to dry the product continuously. The developed dryer consists of 20 tube (1800 mm long)- evacuated tube type solar collector, 4 U-type finned electrical heaters (1kW) and an AC motor (1HP) and blower assembly to provide the required air flow rate. The performance evaluation of designed dryer was done for drying red chilli (CH-27) and compared with sun drying, improved sun drying and mechanical drying. Chillies were given physical pretreatment i.e. chopping; drying kinetics of whole and chopped chillies were studied at 2.5, 5 and 7.5 kg/m2 loading density by sun drying, improved sun drying and mechanical drying technique. The quality parameters included colour, ascorbic acid, capsaicin and colouring matter. Solar assisted mechanical dryer took the minimum time i.e. 54.5 hours to dry whole chillies at 7.5kg/m2 loading density followed by mechanical drying (62 hours), sun drying and improved sun drying both of which took nearly 15 days; accompanied by the lowest final moisture content for both whole (5.20 ± 3.47%) and chopped samples (3.97 ± 1.13%). The quality of the product dried using the developed dryer was found comparable to mechanical drying. 33.69 ± 1.36% saving in energy consumption was observed when solar + electrical mode of designed dryer was used as compared to only electrical heater mode.ThesisItem Restricted Optimization of solar-cum-microwave dehydration of white button mushrooms (Agaricus bisporus)(Punjab Agricultural University, Ludhiana, 2017) Gurpreet Kaur; Satish KumarStudies were carried out on “Optimization of solar-cum-microwave dehydration of button mushrooms”. Drying kinetics of solar, microwave and solar-cum-microwave dried mushroom were analyzed. For optimization of solar-cum-microwave drying process variables viz; moisture content, exposure time and microwave power level, ‘RSM’ 3 - Factor Box–Behnken Design was used for responses, namely; bulk density, rehydration ratio, shrinkage ratio, colour, texture, ascorbic acid, protein content, overall acceptability and specific energy consumption. Logarithmic model showed the highest adequacy of fit for mushroom drying. The highest effective moisture diffusivity (Deff) for solar and microwave was 1.46×10-07 and 6.33×10-06 m2/ s (PL: 1350 and ET: 25 s) respectively. In solar-cum-microwave drying, the highest Deff value of 1.16×10-07 and 2.292×10-05 was recorded for during initial and later stage of drying (PL: 1350 W, ET: 25 s and PL: 25 %). The optimum value of process variables was found to be exposure time: 13.94 s, power level: 270 W and moisture content: 37.92 %. At these optimum value of process variables, the responses were rehydration ratio: 2.03, shrinkage ratio: 0.86, bulk density: 274.63 g/cm3, L: 48.96, a: 4.24, b: 9.36, overall colour change: 16.23, chroma: 10.08, hue angle: 67.96, hardness: 880.40 g-f, chewiness: 575.10 g-f, ascorbic acid: 11.47 mg/100g, protein contet: 23.54 %, overall acceptability: 7.59 and specific energy consumption: 0.19 kWh/kg with an overall desirability of 70.50 %. Model validation showed that there was non-significant difference (5 % level) between the predicted and experimental values of all quality parameters except shrinkage ratio, chroma, hardness, ascorbic acid and specific energy consumption. Mushrooms packed in laminate and stored under refrigerated conditions retained the quality of dried product for three months.ThesisItem Open Access Engineering characterization of kinnow and tomato for grading using image processing(Punjab Agricultural University, Ludhiana, 2017) Sandhya; Mahesh KumarThe present study was undertaken for characterization of kinnow and tomato based on engineering parameters using digital image processing. The images of kinnow and tomato of different grades were acquired using a digital camera. An algorithm using MATLAB was developed to quantify and process these digital images. The geometric parameters such as axial dimensions, mass, volume, density, sphericity, aspect ratio and ellipsoid ratio were recorded. The size of kinnow varied between 62.50-87.41 mm while tomato had size varying from 30.00-77.62 mm. Results of image analysis showed variation of major axis length from 1597.21 pixels to 1987.1 pixels for kinnow. The bulk density was found to be maximum (0.40 g/cc) for kinnow having size 72-74mm whereas it was highest (0.26 g/cc) for tomato of size 57-66mm. The sphericity varied in the range of 0.92-0.94 for kinnow while tomatoes of variety Punjab Chhuhara were found to be oblong. The results obtained by digital image analysis were compared and verified with the experimental observation recorded by vernier caliper. The volume computed from the images of longitudinal view and lateral view of kinnow and tomato of all the grades showed good correlation with the true volume measured by water displacement method. The Bland-Altman approach was used to plot the agreement between the values measured by both the methods and differences between two methods were normally distributed and were estimated to lie between M - 1.96SD and M + 1.96SD, known as 95% limits of agreement. The paired samples t-test results showed that parameters determined with image processing method was not significantly (P>0.05) different from the same parameters measured with vernier caliper. A linear relationship between mass of the kinnow and tomato and the projected area, volume and axial dimensions was also developed for prediction of mass using image processing.ThesisItem Restricted Optimization of greenhouse drying process for white button mushroom (Agaricus bisporus)(Punjab Agricultural University, Ludhiana, 2016) Sidhu, Jashandeep Singh; Amarjit SinghThe present study entitled “Studies on optimization of greenhouse drying process for white button mushroom (Agaricus bisporous)” was carried out in the Department of Processing and Food Engineering, Punjab Agricultural University. Mushrooms were pretreated with citric acid and samples without treatment were kept as control. The treated and untreated mushroom samples were dried in greenhouse and open sun during the month of October, 2015.On the basis of microclimate parameters, a mathematical thermal model “BITGREEN” for greenhouse was developed to optimize the drying conditions. The developed model was working satisfactorily to predict the microclimate inside the greenhouse. The drying parameters studied were moisture content, moisture ratio, drying rate, drying air temperatures, solar intensity and relative humidity. The quality parameters included rehydration ratio, shrinkage ratio, colour, texture (hardness), bulk density, protein content and overall acceptability. Moisture content of dehydrated mushrooms reduced from 88-90 (% wb) to 6.5 (% wb) for greenhouse drying (28-46°C) in 48 hours and 8.2 (% wb) for open sun drying (25-32°C) in 72 hours. The Lewis model showed best adequacy of fit for drying of mushrooms. The dried mushrooms were packed in two packaging materials viz. LDPE and PP and stored under refrigerated and ambient conditions for three months. The quality attributes of stored product like colour, texture, rehydration ratio, shrinkage ratio, water gain and overall acceptability were evaluated at 15 days interval. The greenhouse dried mushrooms packed in polypropylene (PP) and stored under refrigerated conditions were found to be highly acceptable upto 75 days of storage. Benefit-Cost ratio of 1.36:1 for subsidized greenhouse revealed that it is profitable to dry mushrooms in greenhouse.ThesisItem Open Access Development of Oil Extraction Method from Kinnow Peel(Punjab Agricultural University, Ludhiana, 2016) Sharma, Pallavi; Tarsem ChandThe study was conducted to develop an oil extraction method from kinnow peel on the basis of shredding of flavedo layer. Mechanical and Solar drying of peel was performed and drying kinetics and physico-chemical characteristics were evaluated. Oil was extracted from fresh peel either by using physical or hydrodistillation method alone or in combination whereas only hydrodistillation method was used in case of dried peel. Qualitative and quantitative analysis of the oil was done. It was observed that oil yield in physical method was 0.179% with a shredding efficiency and extraction time of 88.94% and 25 minutes respectively. The initial and final moisture content of kinnow peel was 316-354.80% and 7.06-7.4% respectively. Luminous intensity and yellowness of peel decreased significantly (p<0.05) in both mechanical and solar drying. Colour difference (∆E) of kinnow peel ranged from 15.33-18.36. Oil retention capacity, total phenols, flavanols, total antioxidant capacity and swelling index decreased significantly (p<0.05) on drying whereas water retention capacity and solubility increased. Highest oil yield was obtained from hydrodistillation from mechanically dried powder. Colour values of varied significantly (p<0.05) with respect to oil extraction method. Physically extracted oil showed highest redness (a) value and whereas highest yellowness (b) was shown by hydrodistilled oil from fresh peel. Saponification value, acid value, specific gravity, refractive index of oil ranged from 181.73-186.90 mg KOH/ g oil, 3.46-5.023 mg KOH / g oil, 0.803-0.856 and1.352-1.486 respectively.