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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 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.ThesisItem Open Access Design and Optimization of Modified Atmosphere Packaging for black carrot (Dacus carota L.)(Punjab Agricultural University, Ludhiana, 2016) Singla, Mohit; Ashok KumarThe present study was undertaken to Design and optimization of Modified Atmosphere Packaging (MAP) for black carrot (Dacus carota 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 black carrot at different temperatures viz. 5, 10 and 15°C were determined. The respiration rate was described assuming the mixed model 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 black carrot. 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. Black carrot was packed in LDPE and stored under different conditions such as film thickness: 100, 150, 200 gauge; package fill weight = 100, 300, 500g; level of perforations: 0, 2, 4; storage temperature: 5, 10, 15°C. The qualitative analysis of black carrot throughout the storage study was done in terms physiological loss in weight, total colour difference, firmness, total soluble solids, antioxidants, flavonoids and anthocyanins. 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 black carrot during its storage. MAP along with low temperature storage helped in enhancing shelf life of fresh black carrot upto 24 days. The optimized conditions obtained for shelf life extension of black carrot under MAP by using response surface methodology was temperature: 5°C, film thickness: 200 gauge, fill weight: 500 g, perforations: 0.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 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 Optimization of Osmo-Cum-Microwave Dehydration Process for Oyster Mushrooms (Pleurotus sajor-caju)(Punjab Agricultural University, Ludhiana, 2014) Ramya, HG; Satish KumarInvestigations were carried out on “Optimization of Osmo-Cum-Microwave Dehydration Process for Oyster Mushrooms (Pleurotus sajor-caju)”. The effect of various independent process parameters on mass transfer kinetics (water loss and solute gain) was studied. These process variables include solution concentration (salt: 10–20%; salt-sugar: 15 – (45- 65) °B), solution temperature (30–60° C) immersion time (15–240 min) and solution to fruit ratio (4:1 to 8:1). Water loss and solute gain increased with solution temperature, solution concentration, duration of osmosis over the entire osmotic dehydration process. The moisture content reduced from 90.3 to 45 - 48 % (wb). Effective water diffusivity varied between 1.13 - 2.58 x 10-9 m2/s and 1.59 - 3.0x 10-9 m2/s, solute diffusivity between 3.92 - 9.9 x 10-10 m2/s and 9.44 x 10-10 - 1.02 x 10-9 m2/s respectively for mushrooms treated with salt and salt-sugar respectively. Power and Page models showed the highest adequacy of fit for osmotic dehydration of mushrooms treated with salt and salt-sugar solutions respectively. Optimum operating conditions found were: solution temperature – 45o C, immersion time – 53.54 min, salt concentration – 14.09% and solution to fruit ratio 6.08:1. Corresponding optimum values for mushrooms treated with salt solution were, 38.13, 2.1 and 36.02 (g/100 g initial mass) for water loss, solute gain and weight reduction respectively. Optimum operating conditions for mushrooms treated with salt-sugar were, solution temperature – 42.3° C, immersion time – 44.21 min, salt-sugar concentration – 15 %: 52.57° B and solution to fruit ratio 4.99:1. At these optimum values, water loss, solute gain and weight reduction was 41, 2.15 and 38.6 (g/100 g initial mass). Microwave dehydration of pre-osmosed mushroom was carried out at three power levels of 540, 810 and 1080 W. Moisture content of dehydrated mushroom reduced from 45 - 48 to 5.7 – 6 % (wb). Effective moisture diffusivities varied between 1.18 - 2.027x10-9 m2 /s and 1.29 - 2.65x10-9 m2 /s for mushrooms treated with salt and salt-sugar respectively. Logarithmic model showed the highest adequacy of fit for microwave dehydration in the both the cases. The quality of dehydrated mushrooms viz. colour, texture, rehydration ratio, shrinkage ratio and overall acceptability were analyzed for optimization of drying process variables. The optimum condition of microwave drying found were; microwave power level - 810W, L - 48.77, a - 4.41, b - 10.91, ∆E - 10.24, hardness - 1639.56 g-f, chewiness - 429.05 g/cm2, RR - 1.94, SR - 0.93, aw - 0.461, ascorbic acid - 1.8 with an overall acceptability of 80.5 %, for dehydrated mushrooms treated with salt. For mushroom treated with salt-sugar, optimum conditions of microwave drying found were; microwave power level - 810 W, L - 46.66, a - 5.8, b - 15.74, ∆E - 14.15, hardness - 1342.05 g-f, chewiness - 1270.97 g/cm2, RR - 1.89, SR - 0.93, aw - 0.453, ascorbic acid - 1.87 with an overall acceptability of 83 %. The best dried product obtained through optimization was packed in three materials viz; LDPE, HDPE and LAP and stored under refrigerated and ambient conditions for 3 months. The quality attributes of stored product like colour, texture, rehydration ratio, moisture content, water activity, ascorbic acid and overall acceptability were evaluated at 15 days interval. The dried mushrooms packed in laminated aluminium were found to be highly acceptable up to 3 months of storage.