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1.
《Food microbiology》1994,11(1):47-55
Kinema, a soybean fermented alkaline food, is a meat substitute to a majority of the people of the eastern Himalayan regions. The moisture content of kinema was 62%; on dry weight basis, kinema contained about 48% protein, 17% fat, 28% carbohydrate and 7% ash; the energy value was 2·0 MJ/100 g. The corresponding values in raw soybeans were 11%, 47%, 22%, 26%, 5% and 2·1 MJ/100 g. While the pH of raw soybeans was neutral to slightly acidic (average 6·75), that of kinema was distinctly alkaline (average 7·89). Free fatty acidity in kinema was about 33 times higher than raw soybeans. A total of 502 bacterial strains representing Bacillus subtilis and Enterococcus faecium, and 198 yeast strains representing Candida parapsilosis and Geotrichum candidum were isolated from 50 samples of kinema. Bacillus subtilis was the only micro-organism recovered in raw soybeans. In kinema, B. subtilis most dominant (3-5 × 108 cfu g-1 wet weight) followed by E. faecium (5-9 × 107 cfu g-1) occurring in all market and laboratory-made samples. The populations of C. parapsilosis occurring in 50-80% samples was 0·3-9 × 10 cfu g-1, and that of G. candidum occurring in 40-50% of market samples was 0·8-4 · 10 cfu g-1.  相似文献   

2.
This study reports on the effects of roasting on the chemical composition of maize (Zea mays). Proximate analysis showed no significant difference (p > 0·05) between raw and roasted maize in ether extract, crude protein, crude fibre, ash and carbohydrate content; except moisture content (p < 0·05), which showed a 42·3% decrease. Elemental composition analysis showed decreases of potassium (13·8%) and calcium (41·1%). Significant differences (p < 0·05) were observed for vitamins B1, B2 and C contents with 26·8%, 32·4% and 35·1% destruction, respectively. Amino acid analysis showed losses for lysine (26·7%), iso-leucine (20·8%) and leucine (23·4%).There was significant (p < 0·05) variation in phytic acid, oxalic acid, tannin and hydrocyanic acid with reductions of 15·4%, 6·02%, 51·3% and 34·6% respectively.The effect of these changes on the nutritive value of roasted maize is discussed.  相似文献   

3.
Sensory and physical characteristics of miondo made with three types of cassava flour (CF) (CF1, shredding of roots and drying; CF2, shredding of roots, 24-h natural fermentation, and drying; CF3, 3-day steeping of roots and drying) containing 0, 5 and 10% of added soybean flour (SF) were evaluated after 0, 1, 2, 3 and 4 h of resting (RT) before cooking to determine the optimum CF and SF levels and RT. Results indicated that miondo made with CF3 were more palatable (P<0·05) and firmer (P<0·05) than those of CF1 and CF2. Upon resting, there was no significant changes in sensory characteristics of cooked miondo, although the instrumental firmness (hardness) of miondo (made with CF3) increased (P<0·05). Upon addition of SF, products became less palatable, more yellow in colour, softer, less sticky; weight loss of raw miondo decreased; water retention ratio (WRR), crude protein contents, and total ashes of CF3 increased. WRR and protein content of CF3–SF blends correlated negatively with hardness of miondo (r=-0·90 and -0·99, respectively). CF3 with no added SF was most appropriate for making palatable miondo, regardless of the resting time. © 1998 SCI.  相似文献   

4.
The effect of village processing techniques on the aflatoxin content of corn and peanut products was investigated. In 30 trials, corn kernels were dehulled (bran removal), soaked for 24 h, washed and dried before grinding into flour and boiling in water to a thick consistency (Nshima). Shelled peanuts were either dry-roasted as whole kernels or ground into peanut meal and cooked. Dehulling, following by 24-h soaking (steeping) and subsequent washing significantly (P<0·05) reduced the aflatoxin B1 content of corn flour from 900 to 150 μg kg−1, and similarly that of aflatoxin G1 from 929 to 114 μg kg−1. Preparation of Nshima did not result into a substantial reduction in aflatoxin content, neither did extension of the cooking duration of 2 h afford any further decontamination. Whereas boiling peanut meal yielded a moderate reduction in the content of aflatoxins B1 and G1, roasting whole peanut kernels greatly reduced (P<0·001) the concentrations of the toxins from that in raw kernels (AFB1= 8600 μg kg−1 and AFG1=6200 μg kg−1) to 1300 and 1200 μg kg−1, respectively. These results indicate that specific processing techniques carried out in Zambian villages are effective in reducing aflatoxin carry-over into edible fractions, while others are not. © 1998 SCI.  相似文献   

5.
The accumulation of fumonisin B1 (FB1) and fumonisin B2 (FB2) after inoculation of 14 maize hybrids with Fusarium moniliforme has been examined in Poland during the seasons 1992–1995. Fumonisins have been detected in all 14 hybrids in amounts ranging from 0·09 mg kg-1 FB1+0·02 mg kg-1 FB2 to 93·2 mg kg-1 FB1+15·8 mg kg-1 FB2. Inoculated ears contained from <1% up to 60% of Fusarium damaged (=mouldy) kernels (FDK). Fumonisins' levels in FDK ranged from 5·1 mg kg-1 FB1+1·4 mg kg-1 FB2 up to 196·0 mg kg-1 FB1+62·0 mg kg-1 FB2. Significant influence of the year of inoculation on ear infection and fumonisins accumulation was observed. Only one hybrid (Mona) exhibited low disease score, low percentage of FDK (1·1–2·6%) and low levels of fumonisins (FB1 from 0·09 to 1·66 mg kg-1 and FB2 from 0·02 to 0·42 mg kg-1) during 3 years of experiments. © 1997 SCI.  相似文献   

6.
Quality protein maize (QPM) experimental hybrids and normal maize possessing different physical and chemical properties were studied as the raw material for wet milling. Maize samples were steeped for 36 h in a 600-ml solution containing 15 g kg−1 lactic acid and 0·5 g kg−1 SO2 followed by 12 h in a second 600-ml solution containing 5 g kg−1 lactic acid and 1 g kg−1 SO2. The steeped grain was then wet milled and the yields and purity of fractions were analysed. Water-soluble solids, kernel size, quality protein, total dietary fibre and ash content were higher in QPM samples than in normal maize. Water-soluble solids were positively correlated to kernel size ( r =0·97, P< 0·05), test weight ( r =0·83, P< 0·05) and density ( r =0·57, P< 0·05). Total fraction recovery for the five hybrids tested ranged from 921 to 955 g kg−1, with the highest values corresponding to QPM hybrids. QPM hybrids yielded slightly higher starch content than normal maize. Gluten yields of QPM-HO (high oil) presented the highest values. The lysine contents of kernel, gluten and milling solubles were highest for QPM hybrids. QPM contained more palmitic acid than the other hybrids. The H-137 normal maize and QPM yellow dent-HO contained more oleic and linolenic acids than the other samples, and the QPM white-C (corneous) contained more linoleic acid than QPM-HO and normal maize.  相似文献   

7.
Experiments were carried out to find ways to prevent undesirably high nitrate contents in lettuce and high nitrate and oxalate contents in spinach. Treatments included manipulating the soil nutrient supply and the effects of processing and cooking on the reduction of nitrate and oxalate contents, and the maintenance of vitamins and minerals in the spinach. Best lettuce and spinach qualities, ie highest vitamin and mineral contents with lowest nitrate and oxalate levels, were achieved by fertilising them either with farm yard manure (FYM) or Ca(NO3)2+(NH4)2SO4(1: 1)+N-serve (nitrification inhibitor), at the rate of 178·5 kg N ha-1. High spinach yields were also obtained by fertilisation with urea at 178·5 kg N ha-1, but resulted in high nitrate and oxalate levels. Losses of vitamins A, B1, B2, niacin and C as well as minerals Ca, Fe, Mg, Na, K and P from spinach were smaller following freezing compared with canning, especially when 0·1% calcium citrate and 0·01% sodium ascorbate solutions were used for blanching at ∽77°C for 2 min. © 1997 SCI.  相似文献   

8.
Six colour-flowering (Scirocco, Alfred, Carola, Condor, Tina and Herz Freya) and six white-flowering (Caspar, Albatros, Gloria, Tyrol, Vasco and Cresta) cultivars of Vicia faba were studied. The crude protein contents of colour- and white-flowering cultivars were 267±13·6 and 283±18·8 g kg−1, respectively, which did not differ significantly at P<0·05. The levels of lipids, crude fibre, starch and ash varied from 14 to 22 g kg−1, 88 to 143 g kg−1, 407 to 485 g kg−1 and 32 to 42 g kg−1, respectively. The calculated organic matter digestibility (OMD) and metabolisable energy (ME) of the white-flowering cultivars were significantly higher (P<0·001) than those of the colour-flowering cultivars (OMD: 889·1±26·6 g kg−1 vs 797·5±17·1 g kg−1; ME: 13·97±0·49 vs 12·30±0·34 MJ kg−1). In all cultivars, sulphur amino acids were lower than adequate concentration when compared with recommended amino acid pattern of FAO/WHO/UNO reference protein for a 2–5-year-old child. The in vitro rumen nitrogen degradability of colour-flowering cultivars was significantly lower (P<0·01) compared to that of white-flowering cultivars (71·4±9·3% vs 88·0±11·1%). Amongst colour-flowering varieties, the contents of total phenols (TP), tannins (T) and condensed tannins (CT) were highest in Alfred (28·3, 21·0 and 35·4 g kg−1, respectively). The contents of TP and T were similar (about 15 and 10 g kg−1, respectively) in Carola, Tina and Herz Freya, and the CT were in the order: Condor>Herz Freya>Carola. The CT were not detected in white-flowering varieties, T were virtually absent and TP were extremely low (4·0–4·9 g kg−1). The activities of other antinutritional factors (white- and colour-flowering cultivars, respectively: trypsin inhibitor activity 3·05±0·34 and 1·85±0·09 mg trypsin inhibited g−1; lectin 27·2±9·4 and 27·1±5·1 mg ml−1 assay medium producing haemagglutination; phytate 15·0±2·7 and 16·6±2·3 g kg−1) were very low. A strong negative correlation (r=-0·92, P<0·001) between tannins and in vitro rumen protein degradability was observed which suggested that tannins have adverse effect on protein degradability. Similarly negative correlations between tannin levels and metabolisable energy (r=-0·89; P<0·001) and organic matter digestibility (r=-0·89; P<0·001) were observed. The correlation coefficient between trypsin inhibitor activity and tannins was negative and highly significant (r=-0·88, P<0·001), whereas between tannins and saponins it was significantly positive (r=0·96, P<0·001). ©1997 SCI  相似文献   

9.
Eight 1st-lactation cows were given four dietary treatments in a duplicated 4×4 Latin square experiment. Diets consisted of hay and soya bean meal together with barley, formaldehyde-treated barley, oats or formaldehydetreated oats (approximately 34:12:54 on a dry matter basis). Barley diets supplied 211 g fatty acids d?1, oats diets supplied 537 g d?1. The fatty acid composition (g kg?1 total fatty acids) for barley diets was: 300 (16:0); 20 (18:0); 150 (18:1); 470 (18:2); 60 (18:3). Corresponding values for oats diets were 180, 20, 390, 380 and 30 g kg?1. Formaldehyde treatment of the cereals tended to increase milk yield and reduce milk fat content (P<0·01 for barley) but did not affect milk fatty acid composition. Feeding oats in replacement for barley significantly (P<0·05) increased milk yield and lactose yield and reduced milk fat content (P<0·05 for the untreated cereals) and protein contents (P<0·01) without significant effects on milk fat or protein yields. Oats diets led to significant (P<0·001) reductions in the content of 8:0–16:0 fatty acids in milk fat with associated increases (P<0·001) in the content of 18:0 and 18:1. Changes in milk fat content of 18:2 and 18:3 acids were small. The results show the inclusion of oats in the cow's diet to be a means of reducing the saturated fatty acid content of milk fat thereby improving the nutritional value of milk and milk products and their appeal to the health-conscious consumer.  相似文献   

10.
Lectin activity in a toxic (Cape Verde) and non-toxic (Mexico) variety of Jatropha curcas seed meal was investigated using latex agglutination and haemagglutination assays. Lectin activity expressed as reciprocal of the minimum quantity (in mg) of Jatropha meal per ml of the assay mixture which produced agglutination with the latex beads was 2·88 ± 0·57 and 1·71 ± 0·00 (mean ± SD, n = 3) for the toxic and the non-toxic varieties, respectively, which did not differ significantly (P > 0·05), while with the haemagglutination assay these values were 102 and 51, respectively, and differed significantly (P < 0·05). The lectins were inactivated by heating and moist heat was more effective than dry heat. The results suggest that lectins may not be responsible for short term toxicity caused by consumption of raw Jatropha meal. © 1998 SCI.  相似文献   

11.
The aim of the present study was to investigate the effects of additions of various vitamins (B1, B6, B9, B12, and C) and minerals (CuSO4·H2O, MnSO4·H2O, and Na3PO4·12 H2O) on the propagation of kefir grains. The activated kefir grains were inoculated into very low fat (0.1%) cows’ milk under constant temperature (25°C) and impeller speed (100 rpm) for a propagation time of 24 h. After evaluation of the experimental data, the most influential mineral addition providing 39% increase of kefir grain biomass was found to be Na3PO4·12 H2O with a concentration of 0.30 g phosphate (PO4 3?) ion/L. At this optimal condition, a model was also derived for the kefir grain biomass concentration representing pH dependence. This study demonstrated the basis for further research in the direction of kefir grain biomass growth considering the effect of additions of vitamins and minerals to other researchers working in the same field and to dairy industry as well.  相似文献   

12.
The effect of germination on the free and glycosylated B6 vitamers (pyridoxine, pyridoxal, pyridoxamine and glycosylated pyridoxine), thiamin and riboflavin content in pea seed (Pisum sativum L, var Esla) was investigated. In raw peas, the total vitamin B6 content (sum of all vitamers expressed as pyridoxine) was 2.183 mg kg−1 DM. Pyridoxine was found to be the predominant B6 vitamer, while only a little amount of glycosylated pyridoxine, the vitamer with the lowest boiavailability, was observed. Thiamin and riboflavin content in raw peas was found to be 7.614 and 2.110 mg kg −1 DM, respectively. After 6 days of germination, carried out at 20°C, in the dark and with daily rinsing, a significant increase of the total vitamin B6 content, mainly due to the increase of glycosylated pyridoxine, was observed. The content of pyridoxal and riboflavin increased in peas 7.5 and 2 times, respectively, whereas pyridoxine, pyridoxamine and thiamin decreased by 83, 24 and 25%, respectively, at the end of the experiment. Results obtained for these vitamins during pea germination were fitted to modelling curves in order to predict vitamin content for different germination periods. © 1999 Society of Chemical Industry  相似文献   

13.
Amino acid, vitamin (A, E, B1, B2, B3 and B6), and proximate composition were determined in raw and cooked horse mackerel. The changes in amino acid, vitamin, and proximate content were found to be significant for all cooking methods (frying, grilling, and steaming). Cooking did in general significantly increase the contents of essential, semi-essential, and other amino acids compared to raw fish species. Amino acid contents of grilled mackerel were significantly higher (p < 0.05) than those found in fried and steamed mackerel. The A, E, B2, and B6 vitamin content of fried horse mackerel was found to be significantly (p < 0.05) higher than the grilled and steamed samples. The B1 content of steamed and B3 content of grilled were found higher than the other cooked samples. Moisture, protein, fat, ash, and carbohydrate contents of cooked fish ranged between 56.52% to 61.34%, 20.79% and 23.93%, 13.44% and 19.61%, 1.70% and 2.47%, and 1.02% and 4.36 %, respectively. Fried fish had intermediate fat values, while grilled and steamed fishes had a comparatively low value.  相似文献   

14.
The purpose of this study was to analyse the consequences of applying high pressures (100 and 300 MPa for 5 and 20 min) on characteristics such as water and fat binding properties, texture, colour, microstructure and microbiology of low-fat (90 g kg−1, LF) and high-fat (247 g kg−1, HF) meat emulsions. Pressurising of LF and HF samples at 300 MPa caused a decline (P<0·05) in emulsion stability, which was more pronounced at the higher pressure. The influence of high pressures on emulsion texture varies according to fat content. In HF samples, high pressure caused a decrease (P<0·05) in Kramer shear force and Kramer energy, regardless of pressure intensity or time. Pressurisation generally caused increase (P<0·05) in the colour lightness parameter in sausages; the effect on redness and yellowness, however, was dependent on fat content, pressure intensity and pressure time. © 1997 SCI.  相似文献   

15.
The effect of cooking on the nutritive value of koko/kosai was assessed by chemical analysis. There was significant loss in the proximate composition due to cooking. In addition, losses of some mineral elements and vitamins were observed. The losses in potassium, iron, zinc and phosphorus were found to be 23%, 6·7%, 25% and 13·3%, respectively.Losses of vitamins B1, B2, C and carotene were found to be 20%, 46%, 37% and 9·6%, respectively.The amino acid pattern of the koko/kosai was only slightly affected by the traditional method of cooking employed. Some suggestions and recommendations are made on how to retain most of the nutrients when cooking the meals.  相似文献   

16.
The chemical composition and nutritive value of the seeds of African breadfruit, Treculia africana, Decne var. Africana, have been investigated.Analysis of the seeds showed that they contained, in terms of dry weight, 13·4% protein, 18·9% lipid, 58·1% carbohydrate, 1·4% crude fibre and 2·1% ash. The moisture content was found to be 7·8% in terms of wet weight.The mineral elements determined were Na, 7·0mg%; Mg, 184mg%; Ca, 17·5mg%; K, 585mg%; P, 382mg%; Cu, 3·9mg%; Fe, 1·6mg%; Cr, 0·20mg% and Zn, 7·5mg%.Vitamins B1, 0·5mg%; B2, 0·3mg% C, 45·1mg% and β-carotene, 6·0mg% were found to be present in the seeds. The levels of some toxic substances in the seeds were oxalate (soluble), 2·5mg% (total), 3·0mg%; phytate, 2·0mg%; tannin, 15·0mg% and HCN, 1·1mg%. The amino acid composition of the seeds has been studied and the results show that some amino acids are present at high concentrations whilst others are present at only low, or undetectable, levels.  相似文献   

17.
The objectives of this study were to determine the chemical and ruminal nutrient degradability characteristics of two hulled (Calibre and AC Mustang) and one hull-less (AC Belmont) oat varieties. Ruminal nutrient degradability characteristics of the oat varieties were determined relative to barley using one ruminally fistulated cow. Neutral (NDF) and acid (ADF) detergent fibre levels were higher (P < 0·05) in hulled than hull-less oats. Hulled AC Mustang had higher (P < 0·05) NDF and ADF content than hulled Calibre. Starch content was higher (P < 0·05) in AC Belmont (590 g kg−1) than Calibre (457 g kg−1) and was higher in Calibre than AC Mustang (415 g kg−1). Crude protein was higher (P < 0·05) in hull-less than hulled oat. Both hulled varieties had similar CP content (average 124 g kg−1). Estimated digestible energy value was highest (P < 0·05) for AC Belmont (16·94 MJ kg−1), intermediate for Calibre (14·18 MJ kg−1) and lowest for AC Mustang (13·34 MJ kg−1). Ruminal dry matter and NDF degradability were higher (P < 0·05) in hull-less than barley and was higher in barley than hulled oats. Ruminal starch degradability exceeded 900 g kg−1 for all tested feeds and had the order AC Belmont = barley > Calibre = AC Mustang. It was concluded that oat varieties used in this study varied considerably in their chemical composition and ruminal degradability. When compared with barley, hulled oats had lower while hull-less oats had higher ruminal degradability. © 1998 SCI.  相似文献   

18.
Raw goat milk samples from the indigenous Greek breed in the area of Ioannina, northwestern Greece, were collected during one lactation and analyzed for vitamins A, E, B1, B2, and C and for minerals Ca, Mg, P, Na, K, Cu, Fe and Zn. Also, the major constituents of goat milk, namely fat, protein, lactose and solids-non-fat, were determined. The average composition (%) of milk was: fat 4.10, protein 3.36, lactose 4.48 and solids-non-fat 8.54. The mean concentration of the fat-soluble vitamins retinol (A) and α-tocopherol (E) were 0.013 and 0.121 mg/100 ml, respectively. The mean concentration of the water-soluble vitamins, thiamin (B1), riboflavin (B2) and ascorbic acid (C) were 0.260, 0.112 and 5.48 mg/100 ml, respectively. Seasonal variations were observed for all vitamins studied. Thiamin had significantly (P < 0.05) higher concentrations during summer than in winter and early spring. The observed variations of the studied vitamins might be attributed to the differences in the feeding of goats during lactation. The mean mineral contents (mg/100 g) of goat milk were Ca 132, P 97.7, Na 59.4, K 152, Mg 15.87, Cu 0.08, Fe 0.06, Zn 0.37 and Mn 6.53 μg/100 g. Seasonal variations were observed for the major minerals Ca, P, K, and the trace elements Cu and Zn.  相似文献   

19.
Three varieties of green beans (Cleo, Strike and Sentry) were harvested and sorted into four fractions according to pod size (diameter <7 mm; 7–8·5 mm; 8·6–10 mm and >10 mm). Ash content and dietary fibre increased significantly as pod size increased mainly in Cleo and Strike beans. Strike showed the highest fibre content (378·0 g kg−1) but the lowest carbohydrate (364·6 g kg−1) and ash (68·4 g kg−1) values. Mean values for Fe and Mg content were higher in Cleo beans (70·9 and 27·1 mg kg−1, respectively), Zn, Cu and Mg were higher in Strike beans (48·7 mg kg−1, 22·4 mg kg−1 and 3·15 g kg−1, respectively) while Na and Ca values were maximum in Sentry (459·1 mg kg−1 and 7·11 g kg−1, respectively). Trypsin inhibitor was negatively related to in vitro protein digestibility but no relationship was found between this last parameter and phytic acid content. This antinutrient, together with dietary fibre, and a negative influence on in vitro mineral dialysability of green beans. © 1998 SCI  相似文献   

20.
The shoulder, loin and leg from P-class pork carcasses were used to determine the nutrient composition of both raw and cooked cuts. Significantly lower fat content were observed in the current study for the leg (5.21 g/100 g) and loin (6.99 g/100 g) compared to the shoulder cut (10.32 g/100 g). The overall percentage fat for all three cuts was less than 10% which is recommended by the South African Heart Mark. The cooked loin cut contained the most protein (27.50 g/100 g) of the three cooked cuts. When compared to other meat products (beef, mutton and chicken) it is clear that pork is a good source of B vitamins, especially vitamin B3. The cooked loin cut contained the least vitamin B1 (0.22 mg/100 g), B2 (0.02 mg/100 g) but the most vitamin B3 (7.09 mg/100 g), of the three cooked cuts. The 100 g cooked shoulder, loin and leg cuts provide on average 40.11% protein, 5.19% magnesium, 3.37% calcium, 24.29% phosphorus, 18.22% zinc, 22.33% iron and 22.50% vitamin B1, 2.57% vitamin B2 and 42.6% vitamin B3 of Recommended Daily Allowances for males, age 25–50. Energy from a 100 g portion provides 5.81% of the Recommended Daily Allowances. To conclude, the pork cuts are undoubtedly a good source of nutrients that is required for good health because it is high in protein, have a low fat content and are a nutrient-packed choice for the family and compares favourably with the fat, energy, and cholesterol content of many other meats and poultry.  相似文献   

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