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1.
Samples of chicken were prepared using four treatments: (1) manual deboning of whole chickens; (2) manual deboning of skinned chickens; (3) mechanical deboning of whole chickens; (4) mechanical deboning of skinned chickens. The meat was packaged in polyethylene bags, frozen and stored at -18?°C. Treatments 2 and 4 resulted in the lowest fat content. Some minerals, e.g. Fe, Na, Al, K, and Mg did not vary among the four products, while others, e.g. Ca, Zn and Mn were significantly higher in Treatments 3 and 4 compared with Treatments 1 and 2. Cholesterol content was directly proportional to fat content; Treatment 3 gave the highest cholesterol content, while the lowest cholesterol level resulted from Treatment 2. Thiobarbituric acid (TBA) determinations to evaluate oxidative rancidity of fat in the samples showed that Treatments 1 and 3 gave significantly higher values than Treatments 2 and 4.  相似文献   

2.
Regular consumption of dietary antioxidants may reduce the risk of several serious diseases. As vegetables are a major source of antioxidants it is desirable to assess their antioxidant activity and compare different processing and preparation methods. The total antioxidant activity was determined in water- and lipid-soluble extracts from fresh, stored and frozen vegetables. The contribution of individual compounds to total antioxidant activity was estimated. In stored vegetables at ambient or chill temperatures antioxidant activity declined. Blanching and freezing of peas and spinach reduced water-soluble antioxidant activity by 30 and 50%, respectively, thereafter levels remained constant on storage at −20 °C. Samples of frozen peas and spinach purchased from retail outlets had substantially higher antioxidant activity than canned or jarred samples. In a comparison of cooking methods, microwave and boiling for short periods had a negligible effect on total antioxidant activity, but substantial losses occurred after prolonged boiling in water.  相似文献   

3.
Edible portions of Leucopogon parviflorus, Arthropodium strictum, Carpobrotus rossii, Rhagodia candolleana, Typha orientalis, Correa alba, Dianella revoluta and Acacia longifolia were collected in 2017 and 2019 from Warrnambool, Victoria Australia, and studied for phenolics and proximate composition. The plant species recorded consistent antioxidant activity with no nutritional alterations. Except for Alongifolia, total phenolic contents (TPC) were higher in 2019 than 2017 (P < 0.05). All the plant species contained Ca, Mg, Na and K. Except for betanin, isolated from Rcandolleana (700 mg L−1) and Crossii (244 mg L−1), higher quantities of polyphenols were extractable in methanol than water (P < 0.05). The plant fatty acid composition was predominantly palmitic, oleic and linoleic acids with Alongifolia containing 44% linoleic acid. While the plant nutrients and fatty acids were fairly stable, TPCs, some of the minerals and polyphenols varied between the years.  相似文献   

4.
《Food chemistry》2004,88(1):1-6
Different brands of sardines canned in soybean oil and tomato sauce, that are commercialized in Brazil, had their proximate composition, cholesterol content and fatty acids composition analyzed. Protein contents were equivalent to the values found for sardines in natura, ranging from 19.8 to 24.4%. High variations of the total lipids content (5.30–16.8%) were verified; the highest levels were found for sardines canned in soybean oil. The cholesterol content ranged from 50.4 to 65.1 mg/100 g. The highest levels of essential C18:2n  6 and C18:3n  3 fatty acids were found in sardines canned in soybean oil. The EPA (C20:5n  3) and DHA (C22:6n  3) concentrations ranged from 5.39 to 15.1% and from 3.89% to 9.51%, respectively, and the highest levels were observed in sardines canned in tomato sauce.  相似文献   

5.
In this second part of our review, we examine the literature for changes in carotenoids, vitamin E, minerals, and fiber due to processing, storage, and cooking of fresh, frozen, and canned fruits and vegetables. While inconsistencies in methodology and reporting methods complicate interpretation of the data, the results show that these nutrients are generally similar in comparable fresh and processed products. The higher levels of carotenoids typically found in canned as compared to fresh products may be attributed to either reporting results on a wet rather than dry weight basis, greater extractability, or differences in cultivars. There are relatively few studies on processing, storage, and cooking effects on vitamin E in fruits and vegetables. Further research is needed to understand nutritional changes in those few fruits and vegetables rich in vitamin E, such as tomatoes. Minerals and fiber are generally stable to processing, storage, and cooking, but may be lost in peeling and other removal steps during processing. Mineral uptake (e.g., calcium) or addition (e.g., sodium) during processing can change the natural mineral composition of a product. Sodium concerns in canned food can be addressed by choosing products with no salt added. Since nutrient content varies considerably by commodity, cultivar, and postharvest treatments, inclusion of a wide variety of fruits and vegetables in the diet is encouraged. Copyright © 2007 Society of Chemical Industry  相似文献   

6.
Data of contents of vitamins (B1 and B2, C, PP) in production from gidrobionts is given. Is established, that the process of sterilization of canned food from gidrobionts in to container provides significant (almost twofold) decrease (reduction) of vitamins B1 [symbol: see text] B2, smaller losses of vitamin C (less than 30%) and proves to be true sufficient stability (almost on 85-90%) to action of high temperatures (120 degrees C) of vitamin PP. The canned food from sea gidrobionts represent the certain interest basically as a source of vitamin PP, and canned food "Herring smoked in oil"--vitamin B2. The canned food "Skobljanka from cucumber and fish" can be considered as a source of vitamins B2, C, PP.  相似文献   

7.
The effect of processing methods (cooking, frying and smoking) on the chemical composition of two marine fish (Sardinella sp., Dentex sp.) and a freshwater fish (Tilapia sp.) was studied.

The proximate compositions of the fish were similar to those of other fish reported in the literature. Processing per se had no effect on the composition of fish.

Smoking and cooking did not affect the fatty acid composition of the fish. The palm-kernel oil used in frying masked the fatty acid pattern in the fried fish. Freshwater fish contains high levels of n-6 fatty acids. However, similar amounts were found in the freshwater fish and the marine fish. This is probably due to the freshwater fish feeding on mosquito larvae.

The fish contained appreciable amounts of Na, Ca, P and Mg. Trace elements (Fe, Cu, Zn and As) were also determined.

There was no thiamine in flat sardine and tilapia, probably due to thiaminase activity. The content in Dentex sp. was low. Vitamins B2 and B6 were very low in all the fish.  相似文献   


8.
This study evaluated the effect of different cooking methods including blanching, boiling, microwaving and steaming on the content of vitamins in vegetables. True retention was estimated using the yield expressed as a ratio of the weight of the cooked sample to the weight of the raw sample. The retention of vitamin C ranged from 0.0 to 91.1% for all cooked samples. Generally, higher retention of vitamin C was observed after microwaving with the lowest retention recorded after boiling. Cooked vegetables were occasionally higher contents of fat-soluble vitamins, including α-tocopherol and β-carotene, than that of their fresh counterparts, but it depends on the type of vegetables. Microwave cooking caused the greatest loss of vitamin K in crown daisy and mallow; in contrast, it caused the least loss of vitamin K in spinach and chard. Cooking may cause changes to the contents of vitamins, but it depends on vegetables and cooking processes.  相似文献   

9.
The salicylic acid concentration in a range of fresh and canned fruit and vegetables was determined using a sensitive spectrofluorimetric technique. Concentrations in fresh fruit ranged from 0.02 mg kg-1 in kiwifruit to 0.10 mg kg-1 in New Zealand grapefruit, and in fresh vegetables from 0.01 mg kg-1 in cabbage to 0.10 mg kg-1 in whole kernel sweet corn. In canned products, salicylic acid levels ranged from 0.01 mg kg-1 in pears to 0.82 mg kg-1 in cream-style sweet corn. Canned sweet corn and some tomato products had higher levels than the corresponding fresh vegetables. Evidence was obtained to suggest that, in the case of whole kernel sweet corn, the application of heat increased the concentration of free salicylic acid.  相似文献   

10.
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12.
Proximate composition, selected mineral (Zn, Fe, Cd, As, Hg, Pb, Ni, Cu) content and fatty acid profiles were determined in some widely consumed fish species obtained from the Black Sea. All fish species analysed individually were fairly high in protein (14·1–25·1%) and lipid (7·4–18·4%). Moisture and ash content varied within a narrow range. The mineral content was highly variable. The most abundant microelements in fish were Zn and Fe followed by Cu, and the remaining elements were present in amounts below toxic levels. Eight fatty acids (16: 0, 16:1, n-7, 18: 0, 18:1 n-9, 18: 2 n-6, 20:1 n-9, 20: 5 n-3, 22: 6 n-3) represented more than 60% of the fatty acid content. Saturated fatty acids ranged from 25·8 to 45·1%. Anchovy and whiting contained almost 35% of polyunsaturated fatty acids. The percentage of docosahexaenoic acid (DHA) exceeded that of eicosapentaenoic acid (EPA) in almost all the fish species examined, and the actual content of these acids has shown that sprat, whiting, garfish, red mullet, shad and sea bream provide the recommended daily intake of 1 g of EPA+DHA with reasonable amounts of fillet. These results indicate that biological differences existing in fish species can influence the values to be set for the standards and composition. © 1998 Society of Chemical Industry.  相似文献   

13.
The effects of seed treatments, including cooking, popping, germination and flour air classification on several components of Amaranthus caudatus and A. cruentus seeds, including oil, sugars, fibre, minerals and vitamins were studied. The lipid, crude and dietary fibre, ash, and sugar contents were 71, 43, 140, 30 and 18 g kg?1 in raw A. caudatus and 85, 39, 134, 40 and 22 g kg?1 in raw A. cruentus seeds, respectively. Sucrose was the dominant sugar in the raw and thermal treated seeds of both species, while glucose and galactose were the dominant ones in the high protein and the germinated seed flours. Phosphorus, potassium, magnesium and calcium were the dominant minerals in the raw seeds of both species. Air classification increased the content of minerals by more than 35% while thermal treatments did not affect their content and germination increased the calcium and zinc contents. The ascorbic acid contents were 0.030 and 0.023 g kg?1 sample in raw A. caudatus and A. cruentus seeds, respectively. All the treatments reduced the ascorbic acid content, with a high effect for the air classification and the germinated seeds dried at 90 °C. The levels of vitamin B complex, including niacin, niacinamide, pyridoxine and riboflavin were increased in the high protein flour fraction (protein contents of these fractions of A. caudatus and A. cruentus were 263.9 g kg?1 and 246.6 g kg?1, respectively) and decreased in the thermal treated flours. Germination mostly increased the amounts of those vitamins while drying reduced their amounts. Copyright © 2005 Society of Chemical Industry  相似文献   

14.
Lead and cadmium content of some canned fruit and vegetables   总被引:1,自引:0,他引:1  
The levels of lead and cadmium have been determined in samples of canned tomatoes, blackcurrants, grapefruit, pineapples, apricots, oranges, peaches, rhubarb, apples, prunes, damsons, plums, spinach and baked beans. The lead content of the 76 samples was in the range 0.10 to 3.90 parts/million, the mean being 0.56 parts/million; the range and mean of the cadmium content were 0.01 to 0.18 and 0.02 parts/million, respectively.  相似文献   

15.
《Food chemistry》1996,56(2):167-170
The proximate composition, amino acid composition and mineral composition of three different muscles from the legs of seven ostriches were determined. Results indicated that components analyzed remained relatively constant between different muscles. Ostrich meat is characterized by an extremely low intramuscular fat content. Values for water, protein, ash, amino acid and mineral contents are in agreement with values obtained for beef and chicken.  相似文献   

16.
Beans of Phaseolus are an important food crop both economically and nutritionally, and are cultivated and consumed worldwide. With ever rising costs of meats and fresh fruits and vegetables, dry beans are expected to contribute more to the human nutrition in coming years. Traditionally, they have been referred to as "poor man's meat" and have contributed significantly to the diets of many people of several countries in Asia, Africa, Middle East, and South America. In recent years, a renewed interest in bean research in Western European countries and the U.S. is evident. In this review, certain biochemical, technological, nutritional, and toxicological aspects are discussed and the limitations and problems associated with dry beans of Phaseolus as human food are addressed.  相似文献   

17.
Recent developments in the roles of vitamins and minerals in reproduction   总被引:3,自引:0,他引:3  
Vitamins and minerals affect reproductive function. Vitamin A deficiency has long been known to affect reproductive function in cattle. More recently, a role has been proposed for the vitamin A percursor, beta-carotene, in reproductive efficiency. Dietary supplementation with vitamin E and selenium may reduce the incidence of retained placenta, but these nutrients may also affect reproductive function in other ways. Calcium and phosphorus deficiencies affect reproduction in cattle, and vitamin D may directly affect reproductive function in addition to its role in calcium and phosphorus metabolism. Dietary manipulation of a number of other vitamins and minerals also influences reproductive function. However, the specific roles of nutrients in reproductive tissues are not well-defined in dairy cattle, and nutrient requirements for optimal reproductive efficiency in modern dairy cattle deserve careful reevaluation. This review provides a background of the effect of vitamins and minerals on reproduction and it attempts to provide a basis for further investigation of specific mechanisms by which reproductive function is affected. The interface between nutritional science and reproductive physiology provides considerable potential for optimizing reproductive efficiency in dairy cattle.  相似文献   

18.
《Food chemistry》1999,67(1):27-31
Three different aged groups (4-week, 8-week and 18-week) of chickens were obtained from Manisa (in Turkey) Poultry Diseases Research and Vaccine Production Institute. Eleven metals (Cd, Ca, Cu, Fe, Pb, Mg, Mn, Hg, K, Na and Zn) and one non-metal (P) (heart, gizzard, livers, kidneys and spleens and some mineral matter in chicken tissues and meats) were determined using atomic absorption spectrophotometry. A flame photometer was used for determinations of sodium and potassium. After oven-drying of samples, P was determined by a colorimetric method. Proximate and mineral composition of heart, gizzard and meat from different aged group chickens were determined. It is concluded that there is wide variation in metal contents of these tissues.  相似文献   

19.
The influence of consumption of rations containing canned baby foods from mirror carp and Black Sea mullet on severity of system anaphylactic reaction to model food allergen in rats was studied and the level of antibodies to proteins of Black Sea mullet, mirror carp, Alaska Pollack, trout and big head was determined in serum of infants, suffering from food allergy through immune-enzyme analysis.  相似文献   

20.
The fish processing industry produces more than 60% by-products as waste, which includes skin, head, viscera, trimmings, liver, frames, bones, and roes. These by-product wastes contain good amount of protein rich material that are normally processed into low market-value products, such as animal feed, fish meal and fertilizer. In view of utilizing these fish industry wastes, and for increasing the value to several underutilised fish species, protein hydrolysates from fish proteins are being prepared by several researchers all over the world. Fish protein hydrolysates are breakdown products of enzymatic conversion of fish proteins into smaller peptides, which normally contain 2–20 amino acids. In recent years, fish protein hydrolysates have attracted much attention of food biotechnologists due to the availability of large quantities of raw material for the process, and presence of high protein content with good amino acid balance and bioactive peptides (antioxidant, antihypertensive, immunomodulatory and antimicrobial peptides).  相似文献   

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