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20172
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Subject: Processing and Food Engineering × End date: 2017 × Start date: 2017 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Development and evaluation of percussion based machine for quality management of stored grains and their milled products
    (Punjab Agricultural University, Ludhiana, 2017) Jindal, Shilpa; Alam, M.S.
    The study was carried out to develop a machine for non-chemical disinfestation of stored grains and milled products. The machine was designed on the principle of physical disturbance to control the insect-pests of grains /milled products. The developed machine was evaluated for grains (wheat and bengal gram) and their milled products (wheat flour, maida and besan). The developed machine process parameters i.e. Operational speed (OS) (500-1500 rpm for grains and 2000-2800 rpm for milled products) and Number of passes (NOP) (1-3) were optimized using response surface methodology (RSM). Optimization was done aiming at minimum broken % and maximum mortality percentage for grains while the goal for milled products was maximum mortality % with minimum change in size, moisture content and colour. The optimized machine process parameters obtained for disinfestation of wheat grains and bengal gram were 1300 rpm and 1450 rpm OS with one pass respectively. For milled products, the optimized machine parameters obtained were 2800 rpm, 2650 rpm OS with single pass for wheat flour and besan respectively whereas, for maida two pass with 2600 rpm OS was adjudged to be the best. In order to evaluate the efficacy of physical treatment, storage period and packaging material, the samples developed at optimized condition were stored in different packaging material (Steel, PET containers and PP bags) under ambient condition and were monitored for change in quality attributes at 15 days interval. Treatment followed by storage days and packaging material significantly affected (p<0.05) the quality attributes (moisture content, colour change, insect incidence, insect infestation and overall acceptability) of the samples. Machine treated samples showed no change in quality attributes in comparison to untreated sample irrespective of the selected commodity. The samples packed in steel containers were adjudged to be the best in retaining quality of stored product at the end of three months. Overall the developed machine was found to be highly effective in controlling the stored grains and milled product insect-pests.
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    ThesisItemOpen Access
    Effect of Aloe vera gel coating on shelf life and quality attributes of kinnow (Citrus deliciosa Ten.)
    (Punjab Agricultural University, Ludhiana, 2017) Surpreet Kaur; Gupta, Satish Kumar
    Kinnow is the major citrus fruit grown in Punjab and being perishable in nature, it cannot be stored for long periods at ambient conditions. In the present study, the impact of Aloe vera gel coating on quality attributes and shelf life of kinnow was assessed. Four concentrations of Aloe vera gel and water i.e. (0:1), (1:0), (1:1), (2:1) and (3:1) with standard amount of chitosan, pectin and glycerol (1% w/v) were utilized. Kinnow were stored at ambient and refrigerated conditions with LDPE packaging and without packaging. Physio-chemical characteristics- firmness, physiological weight loss, colour, TSS, titrable acidity, ascorbic acid content, TSS/acid ratio, juice content were assessed at an interim of 7 days during storage. The firmness, titrable acidity, ascorbic acid, juice content were gradually decreased more in case of untreated kinnow against the Aloe vera gel coated kinnow during storage. The physiological weight loss, colour change, TSS, TSS/acid ratio were increased during storage under ambient and refrigerated conditions however this increase was more in untreated kinnow when contrasted with treated kinnow. It was concluded that LDPE packed and coated kinnow had better quality and enhance shelf life up to 77 days against the unpacked and untreated kinnow which had 56 days of storage period under refrigerated conditions while in case of ambient storage, LDPE packed and treated kinnow had 10 days of storage while unpacked and untreated kinnow had just 6 days of storage life. It was inferred that Aloe vera gel coating could serve as an alternative option to lessen the post-harvest quality losses and enhance the shelf life of kinnow.