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ThesisItem Embargo Development of process protocol for the production of powder from stevia (stevia rebaudiana)(Punjab Agricultural University, 2023) Kalsi, Baldev Singh; SandhyaStevia rebaudiana leaves, renowned for their natural sweetness, have gained prominence as a healthier alternative to artificial sweeteners. The present research explores various aspects of Stevia leaf processing such as drying, extraction, and grinding, with a vision of optimizing both quality and efficiency. The fresh stevia leaves were dried using different methods: sun drying, convective drying (30-80°C), microwave drying (180 to 900 W) and multistage/hybrid drying: convective pre drying at 50 °C until reaching moisture content of 0.18 g/g, 0.43 g/g and 1.50 on dry basis (db) and then microwave finishing drying at power levels of 360, 540, and 720 W. The Artificial Neural Network (ANN) exhibited a reasonably good fit across all drying conditions to predict drying kinetics, surpassing the maximum R2 range and minimum χ2 and RMSE from the mathematical model. The multistage drying done at 1.50g/g-540W achieved the lowest total color difference (ΔE) value i.e 1.97 compared to other methods, indicating minimal color alteration. Furthermore, ascorbic acid content showed maximum retention after multistage drying at conditions of 1.50g/g-540W (23.50 mg/100g), followed by 1.50g/g-720W (23.04 mg/100g). Further, the total phenolic content also showed excellent results, with multistage drying at 1.50g/g-720W yielding the highest value (58.88 mg GAE/g), followed by 1.50g/g-540W (58.26 mg GAE/g). Additionally, very high antioxidant activity (78.67 %) was retained at the multistage drying at 1.50g/g-540W. The multistage drying at 1.50g/g-540W was selected as best drying as it not only significantly reduced drying time but also preserved the quality and bioactive compounds of Stevia leaves. A lab scale ohmic heating setup was also developed for extracting stevioside and bioactive compounds from dried leaves. The optimization of the ohmic heating assisted-extraction was executed using response surface methodology with temperatures (40-70°C), time (5-15 min) and solvent/ leaf powder ratio (10:1-30:1 ml/g) as independent parameters. The optimized conditions observed were 51.02˚C for 10.297 minutes using Solvent/leaf powder ratio of 30:1 ml/g for maximum stevioside, total phenolic content and antioxidant activity with overall desirability of 0.91. The innovative ohmic heating extraction method proved highly efficient, achieving an approximately 50% higher extraction efficiency for natural compounds from Stevia leaves compared to conventional thermal extraction. Besides enhancing the yield of valuable components, the novel approach also reduces processing time. After considering both visual decolorization and the impact on important quality parameters, the extract decolorized with 1g of activated carbon per 100 ml of stevia extract was deemed the most optimal choice. To combat the hygroscopic nature of Stevia extract powder, inulin (10% w/v) was introduced as an encapsulating agent before the spray drying process. The resulting spray-dried powder displayed favorable characteristics, ensuring improved stability. Moreover, successful crystal formation of stevia powder was achieved using Erythritol. The developed process demonstrated economic viability. In conclusion, this comprehensive study resulted in a process protocol for development of powder from stevia leaves keeping in view consumer preferences.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 Embargo Development of protocol for postharvest quality management of stored mung bean using microwave and ozone(Punjab Agricultural University, 2023) Kulwinder Kaur; Satish KumarThe study aimed to optimize process parameters for ozone gas and microwave energy pre-treatment to maximize the mortality of C. maculatus (also known as pulse beetle) while minimizing the adverse effects on grain quality. Response surface methodology (RSM) was used, employing a Box-Behnken design (3x3) for ozone gas treatment and a full factorial design (2x3) for intermittent microwave heating. The optimized conditions for ozone gas treatment were moisture content: 11.28 %, ozone concentration: 939.98 ppm and exposure time: 2 h. For intermittent microwave heating, the optimal conditions were moisture content: 11.60 %, microwave power level: 435 W at a constant exposure time: 48 s, bed thickness: 4.5 cm, and air velocity: 3 m/s. These optimized conditions resulted in maximum mortality of all stages of C. maculates along with improved grain quality parameters. A grain recirculatory type ozone gas-based fumigation system was designed using Solid Works CAD software. The system showed a saturation time of 21.77 min, a saturated concentration of 1836.96 µg/L, an estimated half-life period of ozone as 10.35 min, and specific energy consumption of 524.62 kJ/kg. The proximate and mineral analysis of mung bean treated in the developed system showed a significant (p<0.05) decrease in protein, fat, and mineral content compared to the untreated samples but it varied non-significantly (p>0.05) vis-à-vis microwave treatment. Fourier Transform Infrared Spectroscope and Scanning Electron Microscope micrographs further confirmed molecular and structural modification in treated mung bean leading to reduced cooking time and enhanced functional, thermal, and pasting properties. The relationship between equilibrium moisture content and water activity predicted storage conditions as safe moisture content at aw 0.6: 11.80- 12.64 %, db and 7.87-13.43 %, db for ozone and microwave-treated mung bean respectively. The storage behavior of treated samples was studied over a 12-months using different packaging materials at retail and bulk levels. Variation in moisture content, headspace CO2 gas, and cumulative weight loss remained within safe limits while phytic acid content, total flavonoid content and antioxidant activity decreased with an increase in storage period with slight variation under high barrier films. Germination percentage was much higher than the Indian minimum Seed Certification Standards and was above 80 % for all treated samples. Ozone and microwave- treated mungbean grains packed in metalized laminated polymer (MLP) or cast polypropylene (CPP) bags at the retail level exhibited the longest shelf life of more than 12 months with acceptable quality, while LDPE (400-gauge) was found suitable for bulk packaging. Techno-economic analysis showed storage of treated and suitably packed grains has the potential to ensure long-term financial stability with an average payback period of less than one year.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 Embargo Development of process protocol for packaging and storage of groundnut kernels(Punjab Agricultural University, Ludhiana, 2022) Gurjeet Kaur; Sidhu, Gagandeep KaurThe spring grown groundnuts are prone to quality deterioration owing to high temperature and relative humidity during the harvesting. The present work investigated the impact of treatments and packaging systems on quality of groundnut kernels during storage. Spring varieties J87 and TG37A developed by Punjab Agricultural University were selected for the study. The fresh groundnut pods were dried using solar hybrid dryer at 60°C till the moisture content below 10% was achieved. Sample was decorticated and clean and healthy kernels were selected for the study. The sorption isotherms were developed at 25, 35 and 45°C temperature and water activity (aw) range of 0.110-0.975 in order to predict the suitable storage conditions. The equilibrium moisture content increased with increase in aw and the isotherms of type II were observed. The experimental data was fitted to seven mathematical models and Guggenheim Anderson de Boer and Double Log Polynomial were considered to be best fitted models. The safe storage conditions determined from best fitted models indicated that moisture content of J87 and TG37A varieties should not exceed 7.70 and 9.86 % (db) respectively during storage. The samples were subjected to three treatments viz. dry roasting (166 °C for 7 min), ozonation treatment (6 mg/L for 30 min) and combined ozonation-roasting (ozonation at 6 mg/L for 30 min followed by dry roasting at 166 °C for 7 min). The groundnut kernels were packed in low-density polyethylene (L), aluminum lined LDPE Ziplock bags (S) and aluminum laminate bags under nitrogen flushing (N) and in high barrier 5-layer polymeric laminate (PE/adhesive/EVOH/adhesive/PE) under vacuum packaging techniques. The samples were kept under ambient conditions for 12 months of storage period. Samples were analyzed for different quality parameters viz., moisture content, color characteristics, fracturability, radical scavenging activity, flavonoid content, protein, free fatty acids and aflatoxin content. Results indicated that treatments led to significantly (p<0.05) affect all the quality parameters except the hue angle and free fatty acids of J87 kernels and hue angle and chroma of TG37A kernels. The aflatoxin content after treatments exhibited values that were below the FDA established limit (20 µg/kg) for aflatoxins in groundnut kernels. The moisture content, chroma, total color difference, free fatty acids were found to be increased and hue angle, fracturability and protein content decreased with increase in storage period. FFA of groundnut kernels packaged in different materials were within acceptable limits (< 3%) for ozonated and ozonated-roasted samples. Radical scavenging activity and flavonoid content indicated a declined trend and then inclined as storage period approached 12 months. The maximum variation in quality parameters were observed in LDPE and zip lock bags. Vacuum and nitrogen flushed bags provided stable conditions with minimum alterations in quality of kernels. Microbial evaluation indicated dominance of Fusarium, Penicillium and Aspergillus spp. which was maximum in zip pouches followed by LDPE bags. It can be concluded that dried groundnut kernels with combined ozonation-roasting treatment, vacuum packaged in 5-layer modified polymeric laminate can be stored at ambient storage conditions for 12 months with maximum retention of quality parameters.ThesisItem Open Access Design, Development and Evaluation of Solar Hybrid Essential Oil Extraction System from Turmeric(Punjab Agricultural University, Ludhiana, 2022) Tiwari, Ravindra Kumar; Mittal, T. C.The present study was conducted to design and develop solar hybrid essential oil extraction system at Department of Processing and Food Engineering, PAU, Ludhiana. The conceptual design of the solar hybrid essential oil extraction system was done for essential oil extraction from turmeric. The system was designed in such a way that it will extract oil from a batch of about 10 kg of raw material. The volume of the distillation unit has a capacity of 0.061m3, the steam generation unit has a capacity of 0.057m3 and the condensing unit has a capacity of 40.50%. The smallest grates size (14.50mm) has the highest oil yield as compared to the largest grates size (17.53mm). The extracted essential oil was evaluated qualitatively in terms of refractive index, specific gravity color, saponification value, acid value, and ester values. The range of various chemical properties are specific gravity (0.89-0.93), refractive index (1.52-1.55), saponification value (35.21-38.13mg KOH/g), ester value (3.59-5.56mg KOH/g), acid values (31.61-32.59mg KOH/g) and colour values are L (32.70-38.90), a (-1 to -5.60) and b (10.6-19.40). The benefit-cost ratio was computed as 1.13 and break-even point for solar hybrid essential oil extraction system can be achieved after 1.85 years. The developed solar hybrid essential oil extraction reduces the extraction time (11.50%), energy consumption (11.75%) and can produce good quality essential oil which is free from wax. This environment friendly developed system lower operating and maintenance costs. The further analysis of the total extraction time and less energy consumption may help in designing a suitable solar hybrid essential oil extraction system with proper control of its operating parameters, and optimization of the process.ThesisItem Open Access Shelf life enhancement of kinnow through active packaging(Punjab Agricultural University, Ludhiana, 2021) Pawandeep Kaur; Kanojia, VarshaKinnow comes in “Mandarin” group of citrus fruits, which produced prominently in India and Pakistan and being perishable in nature. It has the shortest shelf life among all other citrus fruits. The present study was carried out to enhance the shelf life of kinnow by active packaging. RSM with BBD for 3 independent variables at 3 levels viz. dose of scavenger (35grams), fungicide concentration (3-7%) and polythene thickness (100-200guage) was used to optimize the process parameters to maintain the quality of fruit with respect to selected responses i.e., gas composition, physiological loss in weight, firmness, total soluble solids, titrable acidity, ascorbic acid, color difference, microbial load and shelf life. The samples treated with fungicide was packed in LDPE wrapped carton box with O2, CO2 and C2H4 scavenger and stored in cold chamber (5-7°C and 90-95% RH) and were monitored at regular intervals. It was observed that physiochemical properties of kinnow fruit were significantly affected by active packaging (p< 0.05). Optimization was done aiming at minimize O2, CO2, physiological loss in weight, total soluble solids, color difference, microbial load and maximize firmness, titrable acidity, ascorbic acid, shelf life while the process parameters should be within range. The optimized conditions for active packaging of kinnow fruit was 5 grams dose of scavenger, 6.83% fungicide concentration and 192.12 guage of polythene thickness. Corresponding to these variables, the values of O2, CO2, physiological loss in weight, firmness, total soluble solids, titrable acidity, ascorbic acid, color difference, microbial load and shelf life were 12.84%, 3.75%, 7.34%, 4.44 kgf, 9.2°Brix, 1.72%, 35.28 mg/100ml, 0.55, 4.87x103 cfu/ml and 69 days respectively. The overall desirability was 0.812. Value of percentage deviation for validation was less than 5% for all the responses which indicating the precision and reliability of the study.
