No description available.

No description available.

No description available.

The dehydration rates of crabs during low temperature storage and various cooking processes were determined. Season, cooking time, and cooking method significantly affected the weight loss of crabs. The thermal energy (F250 ) crabs received during a commercial cooking process was evaluated by season, cooking method and time, and crab type. The effects of sex, size, and type (sexual maturity) of crab and season on the yields of lump, top flake, bottom flake, and claw and total meat were examined. The effects of cooking time and method and storage time on meat yield was also determined. During summer, male crabs yielded more lump, claw, and total meat than female crabs, and clean female crabs yielded more lump, top flake, and total meat than sponge female crabs when retort cooked for 10 minutes. / Ph. D.

M.S.

The study was designed to develop a nutraceutical product from by-products of fish processing. Fish oil was extracted from mackerel tissues (skin, viscera and muscle) using hexane-isopropanol (3:2 v/v) and chloroform-methanol (2:1 v/v) solvent systems. An oxidative study was carried out to determine the best processing and storage conditions to minimize autooxidation of mackerel oil. Urea complexation was used to concentrate polyunsaturated fatty acids (PUFA) from the extracted fish oil. The urea complexation process was optimized to determine the best reaction conditions for high yield of the omega-3 fatty acids in particular, and total PUFA. / Conjugated linoleic acid (CLA) was synthesized from four vegetable oils (sunflower, canola, soybean and corn) by alkaline isomerization. The CLA isomers and PUFA concentrated from mackerel tissues were used to synthesize triglycerides by lipase-catalyzed esterification. The effect of temperature, reaction medium, enzyme, moisture removal system and glycerol to fatty acid ratio on extent of synthesis were investigated. The synthesis process was also optimized using central composite design to determine the best conditions for high synthesis yield. The fatty acid composition and positional analyses were determined by GC-FID and electrospray ionization mass spectrometry (EI-MS) / The results showed that mackerel skins were most suitable for concentrating PUFA. The eicosapentaenoic acid (EPA) and -docosahexaenoic acid (DHA) content of fish oil from the tissues examined ranged between 6.3--9.7 (wt%) with an iodine value of 134 +/- 5.0. The baseline total PUFA content was increased from ca 21.0 to ca 83.0 (wt%) with an associated iodine value of 296 +/- 7.0 using urea complexation. Low (50 ppm and 100 ppm) levels of alpha-tocopherol in combination with low storage temperature (-40°C) showed lowest oxidation after 66 days of storage. High levels (250 and 500 ppm) of alpha-tocopherol were observed to be prooxidant based on TBARS, peroxide and conjugated diene measurements. Urea to fatty acid ratio and temperature were predominant effectors influencing the amounts of individual omega-3 fatty acids and total PUFA concentrated by urea complexation. The model developed for the optimized urea complexation process were capable of predicting the yields of EPA, DHA, total PUFA and Iodine values to a high degree of accuracy at R2 = 0.87, 0.96, 0.95, and 0.92 respectively. / Sunflower oil was most suitable for synthesizing conjugated linoleic acid by alkaline isomerization, compared with soybean, canola and corn oil. Two CLA isomers, c9,t11 and t10, c12 were most abundant and occurred in approximately equal proportions irrespective of vegetable oil used. Total CLA synthesized from sunflower oil was 93.5 +/- 3.5 (wt%) with the two major isomers making up 89 +/- 3.5 (wt%). Candida antartica lipase showed more synthesis activity than Mucor meihie in both organic and solvent-free systems. Analysis of isolated synthesized triglycerides by GC-FID and mass spectrometry showed that DHA, EPA, CLA and linolenic acid were the main fatty acids incorporated into the triglycerides. DHA and EPA were mostly esterified at the sn-2 position.

The focus of this thesis was on the economic feasibility of three food processing projects. They involved freezing of pork loin and fish using cryogenic freezing and stored at $-$18, $-$12 and $-$7$ sp circ$C, and modified atmosphere packaging (MAP) of pork loin using a combination of nitrogen and carbon dioxide gases, chitosan dip and stored at 5, 10, and 15$ sp circ$C. A production plan with similar layout and capacity was adopted for the Montreal area. The benefit-cost analysis (BCA) of each project was carried out assuming that each plant operated approximately 2000 hours per annum at full capacity. Net present value (NPV) and benefit cost ratio (B/C ratio) at 8% discount rate, and internal rate of return (IRR) were determined for each project. The calculations show the NPV of $2.4 million, $1.8 million, and $3.4 million; B/C ratio of 1.09, 1.09, and 1.10; IRR of 15 %, 13 %, and 18 % for frozen pork loin, frozen fish and MAP pork respectively. All IRRs were higher compared to the 1995 return rates of TSE of 9.7 % and the average return of capital of 8.8 % for some food and beverage industries. These economic values are sensitive to changes in working hours, price of raw materials and finished products. It is also found that MAP products could be stored at temperatures up to 15$ sp circ$C. Frozen products could be stored at temperatures of $-$12$ sp circ$C and below only if the length of distribution chain can be reduced. This would decrease electricity costs up to 36% at each level of distribution. It can be concluded that the three projects are economically profitable.

No description available.

No description available.

Ph. D. / incomplete_metadata