I= POST-HARVEST LOSSES DURING PROCESSING AND PRESERVATION OF FRUITS AND VEGETABLES
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Title of Thesis
POST-HARVEST LOSSES DURING PROCESSING AND PRESERVATION OF FRUITS AND VEGETABLES
Author(s)
Abdul Waheed Khan
Institute/University/Department Details
Institute of Chemistry University of the Punjab Lahore.
Session
1989
Subject
Chemistry
Number of Pages
405
Keywords (Extracted from title, table of contents and abstract of thesis)
Post-harvest Losses, Fruits, Vegetables, shelf-life, Processing, leafy vegetables

Abstract
Post-harvest losses in vegetable have been studied. The maximum(52%) quantitative losses were recorded in spinach of which 25% were at retailer€™s shop. Proximate analysis of vegetables at different stages of maturity indicate that the nutritional composition of the vegetables varied from species to species and with maturity. Protein contents of the leafy vegetables were high (25-46%) at immature stage while roots and tubers indicated 6.9-13.7% protein contents at over-mature stage. Leafy vegetables accumulated more sodium and potassium as compared to the rest of the vegetables. Vitamin contents of all the vegetables were high at mature stage except vitamin of which decreased with maturity. Significant losses in vitamins were observed when the vegetables were stored under conditions comparable with those at retailer€™s shop. Spinach showed a maximum loss of 75% in ascorbic acid during storage at ambient temperature. A maximum loss in ascorbic acid (75.97%) was observed during dehydration of peas.

Different varieties of fruits were harvested at under-rip , ripe and over-rip stages. Proximate analysis showed that fibre, protein, acidity and ascorbic acid decreased with maturity whereas total sugars, vitamin a and mineral contents increased with maturity.

The shelf-life of the fruits was extended when these were stored in pyramidal structures. €œGolden Deli-cious€ variety of apples showed good keeping quality. The losses in nutritive value were almost reduced to 50% in apples and citrus fruits during pyramidal storage. Substantial losses in nutrients were also observed when the fruits were preserved in the form of jam, jelly, preserve, €˜chutney€™, squashes and by solar dehydration. A maximum reduction in ascorbic acid from 1051.0 mg/100 mg to 21.89 mg/100mg was observed when guavas were preserved in the form of guava €˜chutney€™.

Download Full Thesis
2826.45 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
160.31 KB
2 1 Introduction 1
133.5 KB
  1.1 Vegetables 3
  1.2 Fruits 10
  1.3 Importance of the Project 19
3 2 Literature Review 20
187.57 KB
  2.1 Senescence 20
  2.2 Post-Harvest Changes in Fruits and Vegetables 21
  2.3 Methods Commonly Employed to Delay Post-Harvest Senescence 43
4 3 Materials and Methods 52
246.34 KB
  3.1 Procurement of vegetables and fruits 52
  3.2 Storage of vegetables and fruits 52
  3.3 Structure of the Pyramid 53
  3.4 Cleaning, Washing and Preparation of vegetables and fruits for processing 55
  3.5 Processing of Vegetables 55
  3.6 Processing of Fruits 60
  3.7 Chemical analysis of fresh, stored and prepared products of vegetables and fruits 71
  3.8 Organoleptic evaluation of various fruits and fruit products 101
5 4 Results and Discussion 104
1746.38 KB
  4.1 Production of vegetables in Pakistan 104
  4.2 Post-Harvest losses 104
  4.3 Proximate Composition 108
  4.4 Vitamin Losses in vegetables during storage 123
  4.5 Dehydration of vegetables 127
  4.6 Freezing of PEAS 129
  4.7 Evaluation of tomato products 129
  4.8 Fruits 130
6 5 Summary 314
32.94 KB
7 6 References 320
253 KB