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ThesisItem Restricted Optimization of process parameters for refractance window drying of sliced white button mushrooms (Agaricus bisporus)(Punjab Agricultural University, 2024) Chitesh Kumar; Dr Manpreet SinghThe present study was conducted to optimize the process parameters for refractance window drying of mushroom slices. Mushroom slices were dried using refractance window drying system for the optimization of process parameters. Three independent variables at three different levels were selected viz. water temperature (70, 80 and 90 oC), slice thickness (2, 4 and 6 mm) and KMS concentration (0.5, 1.0 and 1.5 %). Out of which, highest drying rate was observed for 2 mm slices dried at 90 oC which decreased with decrease in temperature and increase in slice thickness. Optimization was done using RSM Box-Behnken design (BBD) after which it was confirmed that water temperature of 90 oC, slice thickness of 6 mm and KMS concentration of 1.01 % gave the overall best physico-chemical parameters. The values of responses for dried mushroom slices were, total colour difference: 28.66, total phenolic content: 25.15 (mg GAE/100g dw), bulk density: 0.096 g/cc, antioxidant capacity: 86.23% and protein content: 3.18%. Optimized sample from refractance window drying was then compared with three stage convective tray drying and solar drying. It was observed that pretreated samples dried using refractance window drying had highest drying rates, lowest moisture, highest protein content, bulk density and antioxidant capacity. Also, the total phenolic content was maximum for pretreated solar dried sample which had no significant difference from pretreated refractance window dried sample. Overall colour of both, dried and rehydrated refractance window dried product was also better than the three-stage convective drying and solar drying. Refractance window dried samples were also found to have the highest rehydration ratio and coefficient of rehydration followed by solar dried samples and three stage convective drying samples.ThesisItem Embargo Effect of cold plasma treatment on quality parameters of spinach(Punjab Agricultural University, 2023) Goswami, Kritanjal; SandhyaInvestigations were carried out to study was the effect of cold plasma treatment on spinach quality parameters. Design and development of a plasma setup with an adjustable top portion and strips for adjusting the discharge gap that operated at a 25.00 kHz frequency and a discharge voltage range of 32.00 kV to 47.00 kV. The treatment chamber was made of 8 mm thick glass, aluminum foil and pyrex glass were utilized as dielectric barriers, a switch-mode power supply (SMPS) was used to convert AC power to DC, a voltage controller was in charge of controlling the voltage output, and an EHT component serving as a transformer boosted the voltage. By altering exposure period, discharge gap, sample weight, and output voltage, independent variables were manipulated to optimize the cold plasma system, yielding a desirability value of 0.824. Optimal conditions included 20.00 g sample weight, 3.50 cm discharge gap, and 4.00 min exposure, resulting in desired outcomes: 92.39% moisture content, color value of 7.82, texture at 9.38N, chlorophyll content of 2.94 mg/g, total phenol content of 38.55 mg GAE/g, and microbial load of 2.79 log10 CFU/g. Cold plasma-treated and controlled spinach, stored in both ambient and refrigerated settings, packaged in PP and LDPE, showcases prolonged shelf life, improved moisture retention, color, texture, chlorophyll levels, microbial safety, and flavor preservation in comparison to control spinach. Cold plasma treatment effectively upholds spinach quality in PP packaging, elevating visual appeal, nutrition, and overall freshness for up to 3 days at ambient temperature and 9 days in refrigeration. An economic analysis, considering fixed and variable expenses, estimates a Rs. 57,200/- return over variable cost for the developed cold plasma system post-expenditure. It's important that this cutting-edge method showed little adverse effect on the sensory and nutritional qualities of fresh spinach while appreciably extending its shelf life.ThesisItem Open Access Effect of different precooling methods and storage conditions on shelf life and quality of pear (Pyrus pyrifolia (Burm. F) Nakai)(Punjab Agricultural University, Ludhiana, 2022) Mahajan, Kashika; Gupta, S.K.The present investigation entitled “Effect of different precooling methods and storage conditions on shelf life and quality of pear (Pyrus pyrifolia (Burm. F) Nakai)” was conducted during the year 2021-22. Three methods of pre-cooling i.e; hydrocooling (HC), forced air cooling (FAC) and evaporative cooling (EC) were evaluated for postharvest quality of pear fruit under cold storage and ambient storage conditions. Two experiments were laid out viz (i) Optimization of precooling time of pear fruits using different precooling methods and (ii) Effect of precooling methods on storage life and quality of pear fruit under cold storage and ambient conditions. In the first experiment the data exhibited that HC took 130 minutes and FAC took 360 minutes to precool the pear fruits from 34.9oC to 5.2oC. However, the EC could not achieve the desired temperature to precool the pear fruit. In the second experiment the fruit were subjected to HC, FAC and EC treatments for requisite time period as determined in first experiment. The fruits were packed in corrugated fibre board boxes and stored in cold room (0-1⁰C temp and 90-95% RH) and at ambient conditions (28-32oC and 70-80% RH). The stored samples were evaluated periodically for various physiological and biochemical parameters. The data revealed that FAC was found to be the best precooling method to enhance the shelf life of pear fruits upto 60 days under cold storage conditions and 15 days under ambient storage conditions. The control fruits maintained the storage life upto 45 days under cold storage and 10 days under ambient conditions.ThesisItem Embargo Effect of different packaging films on storage life of tomatoes in consumer packages(Punjab Agricultural University, 2023) Pooja; Sharma, S. R.The present investigation was conducted to evaluate the effect of different packaging films on storage life of tomatoes in consumer packages. Five packaging films HDPE (25μ), LDPE (25μ), PP (25μ), shrink (15μ) and cling (15μ) were used to wrap the consumer packages made of corrugated trays. These film wrapped consumer packages were evaluated for postharvest quality of tomato cv. Punjab Varkha Bahar 4 under ambient and cold storage conditions. The physico-chemical parameters measured to determine the storage life of tomato were PLW, spoilage, firmness, colour, gas concentration, TSS, titratable acidity, total phenols, ascorbic acid and lycopene content at 0, 3, 6, 9, 12 and 15 days of storage under ambient storage conditions (17.4-19 °C, 25-28% RH) and at 0, 7, 14, 21, 28 and 35 days of storage under cold storage conditions (10±1°C and 90-95% RH). Cold storage of tomato was found to be better than ambient storage. Tomato packed in cling film wrapped consumer packages were found to be best for 9 days of storage life with desirable physical and chemical attributes as compared to control packages which maintained the storage life up to 3 days only under ambient storage conditions. Tomatoes packed in cling film wrapped consumer packages proved to be the best for 21 days of storage life with minimum weight loss and spoilage, desirable fruit firmness, better colour and other quality parameters as compared to control packages which maintained the storage life up to 7 days only under cold storage conditions.ThesisItem Restricted Development of biodegradable packaging material from Groundnut shell(Punjab Agricultural University, 2023) Sukhdeep Kaur; Sidhu, Gagandeep KaurThe present study was conducted for the development of biodegradable film from groundnut shell. Different physico-chemical properties viz. moisture content, ash content, bulk density, true density, cellulose content, hemicelluloses content and lignin content were measured using standard methods. Experiments were conducted to investigate the effects of different process parameters viz. shaker time (6, 12 & 18h), shaker speed (160, 180 & 240rpm) and enzyme concentration (80, 100 & 120mg) on lignin content and drying time (10, 20 & 30h), drying temperature (50, 70 & 90◦C), dark or light condition (-1, 0 &1) on cellulose content, lignin content and moisture content on the composition of groundnut shell powder. The results of isolation of lignin from groundnut shell powder The optimization of process parameter was done using response surface methodology (RSM) design trial version 7 Box-Behnken Technique. The biodegradable film from groundnut shell powder was developed by solution casting method. The three types of films viz. agar powder based, mixture of agar powder and peanut shell powder and mixture of agar powder and cellulose microfiber was developed at optimized conditions. The different physico- mechanical properties of different types of films were measured. The maximum thickness was achieved by the cellulose microfiber-based film. The agar-based film had a minimum thickness of 0.18 mm. The transmittance value of agar film was lesser than that of CMF film and PSP. The CMF film's WS percentage decreased in comparison to that of the other two films. CMF film which is made with cellulose and agar, has a higher tensile strength than the other two films. CMF and PSP films had a higher opacity value than agar films. AG films show less weight loss, and when compared to PSP films, It was observed that PSP loses less weight than CMF film in the soil burial degradation test because lignin was present.ThesisItem Embargo Vacuum-assisted osmotic pretreatment induced magnetic freezing of mushroom(Punjab Agricultural University, 2022) Wagh, Muktabai Dinesh; Alam, M. S.Mushroom, extremely perishable in nature having tendency to lose its quality after harvest with a limited shelf life needs a technique to convert it to a self-stable product. Keeping in view the above points, the technique has been developed and optimized/standardized for developing self-stable frozen button mushroom by using developed vacuum impregnation (VI) system and optimized its operational process parameters followed by Magnetic-field assisted freezing (MAF) for whole and sliced mushrooms. The VI process parameters selected were solution temperature (ST) (35-55 °C), salt concentration (SC) (4-12 %), vacuum pressure (VP) (50-170 mbar) and immersion time (IT) (30-90 min) with constant solution to sample ratio (4:1) and were optimized on the basis of maximum water loss (WL), solute gain (SG), ascorbic acid content (AA), titratable acidity (TA), firmness (F) and minimum color change (CC) and pH. In each experimental combinations, desired concentration i.e 1 percent Ascorbic acid and 1 percent Calcium lactate was mixed with the hypertonic salt solution for selected duration by applying desired vacuum for 15 min irrespective of the experimental immersion time followed by restoration at atmospheric pressure. In order to develop frozen mushroom (whole and sliced), the experiments were conducted using MAF setup developed in the department. The system was operated and evaluated using AC and DC supply i.e. alternating magnetic-field assisted freezing (AMAF) and static magnetic-field assisted freezing (SMAF) by varying the operational parameters i.e. intensity of magnetic field, forms of mushroom and type of sample (fresh and vacuum impregnated) and was compared with conventional freezing (control). The samples were evaluated for freezing kinetics (total freezing time, phase change time, freezing rate, freezing temperature and nucleation temperature) thawing loss and physico-chemical properties (AA, TA, F, CC and overall acceptability). The best frozen mushroom (fresh and vacuum impregnated) developed by DC supply was packed in different packaging material (plastic punnets and polypropylene bag) and stored in deep freezer (-22 ºC) and evaluated for its quality changes at regular interval. The optimum values of VI process parameters and responses obtained for whole mushroom were IT-75 min, ST-41°C, SC-10%, VP-140mbar and WL-22.14%, SG-2.31%, AA-28.74mg/100g, TA-0.28%, CC-4.61, F-9.85 N and pH-5.37 respectively with overall desirability of 0.85. The optimum values of VI process parameters and responses obtained for sliced mushroom were IT-60 min, ST-42°C, SC-9% and VP-140 mbar and WL-26.64%, SG-2.91%, AA-34.06 mg/100g, TA-0.35%, CC-4.34, F-6.28 and pH-5.23 respectively with overall desirability of 0.80. It can be concluded that the best frozen sample for MAF was observed at 10 mT under SMAF and the mushroom packed in plastic punnets retained significantly higher physical and nutritional qualities attributes. Overall, the VI system and MAF technique were found effective in maintaining the quality and enhancing the shelf-life of whole as well as sliced mushroom.ThesisItem Restricted Storage behavior of selected food grains in hermetic bag and cocoon bag(Punjab Agricultural University, Ludhiana, 2023) Yadav, Shubham; Mahesh KumarThe present study has been conducted to observe the storage behavior of selected food grains (paddy, wheat and canola) in hermetic bag and cocoon bag. Storage parameters like moisture content, bulk density, thousand grain weight, insect count, mould affected grains percentage, broken grains percentages, grain damaged percentage, level of oxygen and carbon dioxide concentration inside cocoon bag, germination rate and internal environment conditions like temperature and relative humidity has been observed during the study. In case of canola oil seed, acid value of extracted oil has been examined. The techno-economic feasibility of stored grains under prescribed condition has been evaluated out using standard methods. The grains have been stored for 6 months in different types of plastic bags like 1-layer (HDPE), 2-layer (HDPE and PP), 3-layer (2-layer HDPE and PP), jute bag and cocoon bag. The cocoon bag has showed marginal effect on moisture content of food grains viz. 0.50 % variation for paddy, 0.31 % variation for wheat and 0.66 % variation for canola as compared to other storage bags. There was limited variation in bulk density of paddy 0.01 %, wheat 0.006 % and canola 0.0338 % while 1000 grain weight was changed with a very small variation of 0.1448 % for paddy, 0.1117 % for wheat, and 0.9918 % for canola in cocoon bag. After 6 month of storage, 4.6 % oxygen and 78.0 % carbon-di-oxide concentration were maintained inside the cocoon bag and no insect activity was observed in the cocoon bag stored grains and there was no mould affected grains. Broken grains percentages were changed with a very small range in cocoon bag 0.90 to 0.98 for paddy, 1.40 to 1.81 for wheat, and zero for canola. The acid value of canola oil was found to be in the range of 0.97 mg / 100 g of KOH to 0.99 mg / 100 g of KOH in cocoon bag. The profit margin has been worked out be highest in cocoon bag (12.13 %) due to minimum grain loss and limited changed in quality parameters followed by 3-layer hermetic bag with 2.65 % and 1-layer, 2-layer and jute bag has negative profit margin i.e., loss due to damaged grain by insects. Cocoon bag can be adopted through proper training and demonstrated for safe grains storage.ThesisItem Embargo Studies on the impact of vacuum and nitrogen flush packaging on natural ageing of basmati rice(Punjab Agricultural University, Ludhiana, 2022) Aggarwal, Kanika; Mittal, Tarsem ChandThe present research was done to study the impact of vacuum and nitrogen flush packaging on natural ageing of basmati rice. Vacuum and Nitrogen flush packaging is becoming increasingly common. Vacuum packaging is considered to be beneficial for basmati rice storage as it can effectively retard the rice deterioration. Whereas, nitrogen is used as a filler gas to maintain the shape of pack by avoiding packaging collapse due to dissolving of carbon dioxide into the food product. It prevents collapse of package because it is less soluble in fat and water. So, these enable the significant extension in shelf life of product. Storage of the basmati rice in different packaging material, under different conditions, at different period of time and temperatures affects its physicochemical, cooking and textural properties. Two basmati rice varieties (Pusa Basmati 1121 and Pusa Basmati 1718) were stored in three different packaging materials using three different packaging methods for six months under ambient conditions. Packaging materials used were triple layer vacuum packaging material (Pe + Adhesive + Evoh + Adhesive + Pe) (TLM 95 gauge); low density polyethylene (LDPE 100 gauge) and laminated aluminium foil packages (APM 100 gauge). About half kg of Pusa Basmati 1121 paddy and Pusa Basmati 1718 was filled in these bags. Total six bags of each type were accordingly filled. These bags were normal sealed, vacuum packaged and nitrogen flushed. Samples were drawn from each bag at an interval of one month and assessed for various quality parameters like changes in cooking, physicochemical and textural properties during storage. On storage the cooking parameters like optimum cooking time and solid loss in gruel decreases whereas cooking coefficient, water absorption ratio and volume expansion ratio increases. The moisture content, amylose content decreases while aroma, hardness and other textural properties increases with increase in storage period. Storage in triple layer vacuum packaging material under vacuum conditions was founded to be the best to maintain a better quality.ThesisItem Restricted Osmo-assisted convective and solar drying of papaya cubes using different natural sweeteners(Punjab Agricultural University, Ludhiana, 2022) Damanpreet Kaur; Manpreet SinghThe present study was conducted on osmo-assisted convective and solar drying of papaya cubes using different natural sweeteners. Papaya is rich in carbohydrates, vitamin A, calcium, iron, and fibre, as well as phosphorus, lipids, magnesium, and amino acids. Papaya was osmotically dehydrated in sugar, jaggery and honey solutions at varying osmotic temperatures, solution concentrations and osmosis times to evaluate mass transfer kinetics. Experiments were conducted to study the effect of osmotic solutions and process parameters on the physico-chemical quality of osmosed papaya cubes and to compare the quality of intermediate moisture papaya cubes obtained by three-stage convective drying and solar drying of osmosed samples. The optimization of osmosis process parameters was done using response surface methodology (RSM) Box-Behnken technique. The drying parameters viz. moisture content, drying rate, and moisture ratio and the quality parameters viz. total colour difference, bulk density, texture profile analysis, total phenolic content, ascorbic acid content, titratable acidity, antioxidant capacity, total flavonoid content, lycopene content and betacarotene content of the osmo-convective and osmo-solar dried product were determined. The results showed that optimized conditions of osmotic temperature, osmotic solution concentration and osmosis time for different natural sweeteners were found to be sugar: 37.98oC, 57.79o Brix, 5.05h, jaggery: 42.12oC, 48.75o Brix, 5h, honey: 41.17oC, 60 o Brix, 5h on the basis of quality responses. Further, osmosed samples dried in a solar dryer had better ephysicochemical quality than convective tray dried samples. Different drying models were fitted to experimental data to assess their coefficient of determination (R2). It was concluded that irrespective of drying method, honey-osmosed papaya had better overall physicochemical quality while the flavonoids were found to maximum in jaggery osmo-dried samples and phenols were found to be maximum for sugar osmo-dried samples. Furthermore, honeyosmosed samples dried at a faster rate in tray drying while sugar-osmosed samples dried at a faster rate in the case of solar drying.
