Thumbnail Image

Thesis

Browse

20112
Reset filters
Subject: Food Technology × End date: 2013 × Start date: 2010 × Thesis Type: Ph.D ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemRestricted
    UTILIZATION OF SPICES AND HERBS FOR IMPROVEMENT OF QUALITY AND SHELF LIFE OF BAKERY PRODUCTS
    (PAU Ludhiana, 2011) Gurpreet Kaur Dhillon; Amarjeet Kaur
    Present study was aimed to minimize the use of chemical preservatives by replacing them wholly or partially with natural preservatives i.e. spices and herbs in bakery products, without altering the desired quality attributes. Powdered spices and herbs were evaluated for antioxidant activity and total phenolic content. The inhibitory effects of spices and herbs on Aspergillus, Eurotium and Penicillium were evaluated in vitro using PDA (potato dextrose agar) media. Incorporation of spices and herbs modified the farinographic curve characteristic and pasting properties of the dough. Quality and shelf life of bakery products i.e. bread and muffins by incorporating spices and herbs (cinnamon, clove, garlic, oregano and thyme) in bread and muffins at (1, 2, 3 and 4 % level) alone or in combinations were studied. Based on the bread and muffins making and organoleptic quality the level of incorporation of spices and herbs to be used in the standard recipe were selected. Bread with acceptable product quality and organoleptic properties were prepared after incorporation of spices and herbs (2 % cinnamon, 1 % clove, 1 % garlic, 2 % oregano and 2 % thyme) and their combinations i.e. cinnamon : oregano – 2:2, cinnamon : thyme – 2:2, clove : oregano – 1:2. Muffins were made after incorporation of spices and herbs (2 % cinnamon, 1 % clove, 2 % oregano and 2 % thyme) and their combinations were for cinnamon:clove – 2:1, cinnamon : thyme – 2:2 and oregano: thyme – 2:2 with very good product quality and organoleptic properties. Bread prepared after incorporation of best combination of spices and herbs were packed in LDPE and PP and stored under ambient and refrigerated condition for 10 days to study the shelf life of product by estimating periodic changes in moisture content, water activity, free fatty acid, peroxide value, pH, texture and visual mold growth. Spiced bread had a shelf life of 8 and 10 days at ambient and refrigerated temperature, respectively. Similarly, muffins prepared from flour supplemented with best combination of spices and herbs and were packed in LLDPE and stored under ambient and refrigerated conditions for one month to find out shelf life of the product. Muffins prepared from spices and herbs remained acceptable till 28 days at ambient condition and 35 days when stored under refrigerated condition. Combinations of best levels of spices and herbs along with 0.1 per cent calcium propionate or potassium sorbate enhanced the shelf life of bread from 3-4 days to 10-12 days and of muffins from 14 days to 35 days at room temperature.
  • Thumbnail Image
    ThesisItemOpen Access
    ANTIOXIDANT PROPERTIES OF CEREAL BRANS AND THEIR POTENTIAL FOOD APPLICATIONS
    (PAU Ludhiana, 2011) Basharat Nabi Dar; Savita Sharma
    The present investigation was carried out to evaluate the antioxidant and food potentials of cereal brans (wheat, rice and oat) singly and in combination. Conventional and microwave assisted solvent extractions were applied to quantify the antioxidants in cereal brans. Conventional solvent extraction (50, 60 and 700C) and microwave assisted solvent extraction (2450 MHz for 2, 3.5 and 5 min) were performed using acetone, hexane and methanol as solvents. Total phenolic assay, DPPH (2, 2-diphenyl-1-picrylhydrazyl) and TEAC (trolox equivalent antioxidant capacity) were assessed for antioxidant capacity. Highest antioxidant capacity was obtained at 60oC for conventional solvent extraction and 3.5 min for microwave extraction. Among various solvents used methanolic extracts acquired maximum scavenging capacity under both types of extractions. The microwave assisted solvent extraction demonstrated higher results for antioxidants compared to conventional solvent extraction. Rice bran had maximum total phenolic content (mg GAE/g) and percent inhibition of DPPH radical under both types of extraction conditions. Wheat bran displayed highest TEAC in conventional as well as in microwave assisted extraction conditions followed by bran in combination and oat bran. Cereal brans singly and in combination were blended at varying levels for extruded snacks (10, 20 and 30%), breakfast cereal-Porridge (5, 10 and 15%) and chapatti (5 and 10%). Enriched products were assessed for antioxidant assay and quality. The antioxidant activity of bran supplemented products was higher than control. Antioxidant capacity and total phenolics increased significantly with increase in bran level supplementation in resultant product. On the basis of quality assessment, 20% enrichment level for extruded snacks and 10% level for breakfast cereal-Porridge and chapatti was best. Antioxidant activity and product quality was assessed during storage for six months at one month interval. Moisture content, water activity and free fatty acids remained stable during entire storage period. A slight reduction in antioxidant capacity of cereal bran enriched products was noticed with prolonged storage. Antioxidant capacity of cereal brans has positive effect on extending shelf life of cereal bran enriched products. Enriched products were highly acceptable upto 6 months of storage.