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1.
Yaakob B Che Man Wanna Ammawath Russly A Rahman Salmah Yusof 《Journal of the science of food and agriculture》2003,83(5):395-401
The changes in quality characteristics of refined, bleached and deodorized (RBD) palm olein used for deep‐fat frying of banana chips (180°C for 3 min at 17 min intervals for 2 h day?1, to give six fryings per day and 30 fryings over five consecutive days) were studied. Four frying systems were used: RBD palm olein without antioxidant (system 1); RBD palm olein with 0.2 g kg?1 α‐tocopherol (system 2); RBD palm olein with 1 g kg?1 oleoresin rosemary (system 3); and RBD palm olein with the combination of 0.1 g kg?1 α‐tocopherol + 0.5 g kg?1 oleoresin rosemary (system 4). Fried oil samples were analysed for fatty acid composition, peroxide value (PV), anisidine value (AnV), totox value, free fatty acids (FFA) value, iodine value, at 232 and 268 nm, colour and viscosity. The crispness and sensory evaluation of the banana chips fried in this study were also evaluated. The results showed that RBD palm olein with added antioxidant reduced PV, AnV, totox value, at 232 and 268 nm, FFA and viscosity. The order of effectiveness in inhibiting oil oxidation in RBD palm olein was: oleoresin rosemary > α tocopherol + oleoresin rosemary > α‐tocopherol > control. For the crispness, the force values of banana chips fried in all systems were comparable. Sensory evaluation of fried banana chips for each system showed that there was no significant (P > 0.05) difference in terms of colour, flavour, odour, texture and overall acceptability. Copyright © 2003 Society of Chemical Industry 相似文献
2.
Mehmet Kenar Fatih Özogul Esmeray Kuley 《International Journal of Food Science & Technology》2010,45(11):2366-2372
The effect of the natural antioxidants and antimicrobials from ethanol extracts of rosemary and sage tea on sensory, chemical [Total volatile basic nitrogen (TVB‐N), thiobarbituric acid reactive substances (TBARs), peroxide value (PV), free fatty acid (FFA)] and microbiological (total viable count‐TVC and total coliform count) changes of vacuum‐packaged sardine (Sardina pilchardus) fillets stored at 3 ± 1 °C was investigated for 20 days. The fish fillets were divided into three groups: untreated group (control, C) and treated groups that were immersed in a 1 L of distilled water containing 10 g rosemary (R group) or sage tea (S group) extracts for 4 min. The shelf life of sardine fillets was found to be 13 days for control (C), 20 days for R and S groups according to sensory assessment results, whose corresponded microbiological assessment showed a shorter shelf life (5 days for C group, 9 for R and S groups). At the end of storage period, TBARs values were 0.98 mg malonaldehyde kg?1 for C group, 0.66 malonaldehyde kg?1 for R group and 1.44 mg malonaldehyde kg?1 for S group. Microbiological results showed that natural compounds from rosemary and sage tea resulted in a lower bacterial growth in fish fillets during the storage period. 相似文献
3.
İlknur Uçak Yesim Özogul Mustafa Durmuş 《International Journal of Food Science & Technology》2011,46(6):1157-1163
The effects of the use of antioxidant technology on the quality of mackerel burgers stored at 4 °C were investigated in terms of sensory, biochemical [thiobarbituric acid (TBA), total volatile basic nitrogen (TVB‐N), peroxide value (PV) and free fatty acids (FFA)] and microbiological analyses [total viable count (TVC)]. Fish meat was divided into three groups; the control (C) without rosemary extract, the second group with 0.4% rosemary extracts (Group A) and the third with 0.8% rosemary extracts (Group B). Results showed that the TVB‐N level did not exceed acceptability limit (30–35 mg 100 g?1) for all groups. TBA value for the control significantly increased from 1.47 to 4.80 MA kg?1 whereas it slightly increased in treatment groups as the storage time increased. Significantly higher PV and FFA (P < 0.05) were obtained from the control group. Rosemary extract, in combination with vacuum pack was effective in controlling the growth of bacteria and biochemical indices. 相似文献
4.
Yesim Ozogul Deniz Ayas Hatice Yazgan Fatih Ozogul Esmeray K. Boga Gulsun Ozyurt 《International Journal of Food Science & Technology》2010,45(8):1717-1723
The effects of rosemary extract at different levels (%1, R1, and %2, R2) on the quality of vacuum‐packed sardine in terms of sensory, biochemical (thiobarbituric acid, total volatile basic nitrogen, peroxide value and free fatty acids) and microbiological analyses (total viable counts) were investigated. Fish were filleted and divided into three groups. First group was used as the control (C) without rosemary extract, second group was treated with 1% rosemary extracts (10 g L?1) for 2 min (R1), and the third was treated with 2% rosemary extracts (20 g L?1) for 2 min (R2). Thirty fillets per litre were used. After that, all groups were vacuum‐packed in polyethylene bags. The samples were stored in the refrigerator condition (4 ± 1 °C) over the storage period of 20 days. The results showed that the use of rosemary extract improved the sensory quality of both raw and cooked sardine, most preferably sardine treated with 1% of rosemary. Biochemical analysis showed that the use of 2% of rosemary extract were found to be most effective (P < 0.05) in controlling the rate of lipid oxidation. 相似文献
5.
M Antonia Murcia Magdalena Martínez‐Tom Ana Vera Asuncin Morte Almudena Gutierrez Mario Honrubia Antonia M Jimnez 《Journal of the science of food and agriculture》2003,83(6):535-541
Our objectives were to investigate the proximate composition of two desert truffles (Terfezia claveryi Chatin and Picoa juniperi Vittadini) and to determine the effects of freezing and canning on proximate composition. The moisture content of T claveryi and P juniperi was 730.9 g kg?1 and 637.8 g kg?1 respectively; ash was 42.5 g kg?1 and 82.1 g kg?1 respectively; protein was 159.5 g kg?1 and 225.4 g kg?1 respectively; lipids were 69.5 g kg?1 and 199.4 g kg?1 respectively; fibre was 83.2 g kg?1 and 130.4 g kg?1 respectively; and carbohydrates were 645.5 g kg?1 and 366.6 g kg?1 respectively. The fatty acids composition showed high quantities of linoleic acid 18:2 (45.4% in T claveryi and 53.0% in P juniperi), the rest of the fatty acids in decreasing order were 16:0 > 18 : 1 > 18 : 3 18 : 0 + 22 : 0 > 20 : 0 + 24 : 0 > 14 : 0 + 22 : 1 > 15 : 0 + 16 : 1 + 17 : 0 + 21 : 0 in T claveryi and 18 : 1 > 16 : 0 > 18 : 0 + 18 : 3 + 16 : 1 + 20 : 0 + 22 : 1 > 14 : 0 + 24 : 0 > 15 : 0 + 17 : 0 + 22 : 0 in the P juniperi. Little loss of ash, protein and lipids was observed as a result of industrial processing (p < 0.05). Copyright © 2003 Society of Chemical Industry 相似文献
6.
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
7.
Xiaoqiang Chen Ying Zhang Yuangang Zu Lei Yang Qi Lu Wei Wang 《International Journal of Food Science & Technology》2014,49(2):385-391
The antioxidant activities of ethanol extracts of rosemary (Rosmarinus officinalis L.) (RE) were tested in natural sunflower oil stored at 60 °C by measuring their peroxide values (POV), thiobarbituric acid‐reactive substances (TBARS), free fatty acid (FFA) content and p‐anisidine value (AnV) after regular intervals compared with synthetic antioxidants. After 3 weeks of storage at 60 °C, sunflower oil containing 200 mg kg?1 rosemary extracts showed lower POVs (75.7 ± 0.47 meq kg?1), thiobarbituric acid‐reactive substances (TBARS)(0.161 ± 0.002 μg mL?1), FFA contents (0.45 ± 0.04 mg g?1) and AnV (12.4 ± 0.02) than the control sample. Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) showed POVs (204 ± 0.68, 159 ± 0.55, 20 ± 0.49 meq kg?1), thiobarbituric acid‐reactive substances (TBARS) (0.171 ± 0.002, 0.184 ± 0.002, 0.069 ± 0.001 μg mL?1), FFA contents (0.34 ± 0.03, 0.46 ± 0.03, 0.2 ± 0.01 mg g?1) and AnV (14.7 ± 0.03, 16.5 ± 0.04, 6.77 ± 0.01), respectively, after 3 weeks of storage at 60 °C. These results illustrate that rosemary extracts exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT). 相似文献
8.
Jos M del Valle Oscar Rivera Osvaldo Teuber M Teresa Palma 《Journal of the science of food and agriculture》2003,83(13):1349-1356
Hops (Humulus lupulus L) have very stringent requirements of diurnal light hours during flowering. Thus, the beer industry is permanently assessing new agricultural land to grow hops, southern Chile being an excellent candidate for their introduction. Supercritical carbon dioxide extraction procedures were implemented to assess Chilean hop ecotypes. Based on results of a preliminary study with commercial samples (cv Nugget), 200 bar and 40 °C were selected as extraction conditions. Very limited increases in extraction rate were observed when applying pressures >200 bar; such pressures did not speed up the extraction of α‐acids (bitter flavor principles), but rather increased the co‐extraction of undesirable compounds (hard resins and chlorophyll pigments). On the other hand, the effects of retrograde condensation phenomena were just starting to subside at 200 bar, and thermal damage of samples could increase at >40 °C. Ground cone samples of five local hop ecotypes, originating from Osorno, La Junta, Coyhaique and Elizalde Lake, were subsequently tested. Osorno exhibited a higher yield (65 g kg?1 oleoresin/substrate) than other Chilean ecotypes. Moreover, Osorno extract had a light yellowish color, as well as a higher content of bitter flavors (157 g kg?1 α‐acid/extract) and 1.5–7.1 times more representative aroma compounds than extracts of the other ecotypes. However, all these indicators were very low compared with the commercial Nugget sample (134 g kg?1 oleoresin/substrate, 383 g kg?1 α‐acid/extract, 14 times more aroma compounds than Osorno ecotype). Copyright © 2003 Society of Chemical Industry 相似文献
9.
LaChanda M Reeves Mervin L Williams Thomas C Jenkins 《Journal of the science of food and agriculture》1998,77(2):187-192
Disappearance of cis-18:1(n-9) from ruminal in vitro cultures supplemented with either oleic acid or oleamide was measured over 48 h to determine if the amide resisted biohydrogenation. Oleamide added to the substrate maintained higher concentrations of cis-18: 1(n-9) in the microbial cultures at 24 and 48 h of incubation compared to substrates with added oleic acid. Disappearance rates of cis-18: 1(n-9) from the cultures, which were calculated as a measure of biohydrogenation, were 0·064 and 0·025 h−1 for the oleic acid and oleamide supplements, respectively. Four sheep were fed four diets (control, 42 g kg−1 oleic acid, 23 g kg−1 oleamide, and 45 g kg−1 oleamide) in a 4×4 Latin square to determine how the amide affected fatty acid digestibility. Total tract digestibilities of protein and fibre were not affected (P>0·05) by either oleic acid or oleamide compared to the control diet. Fatty acid and energy digestibilities were not changed (P>0·05) by oleic acid, but were increased (P<0·05) when oleamide was added to the sheep diets at 45 g kg−1. These results show that oleamide resists ruminal biohydrogenation without impairing fatty acid digestibility. © 1998 SCI. 相似文献
10.
Anna M Fearon C Sinclair Mayne J Alan M Beattie David W Bruce 《Journal of the science of food and agriculture》2004,84(6):497-504
The effect of including additional oil, incorporated as whole rapeseeds, in the diet of 64 Holstein–Friesian dairy cows (32 mid‐ and 32 late‐lactation) at pasture on animal performance and milk fat composition and properties was followed over a continuous trial of 20 weeks duration. Within two stages of lactation (mid, 130 ± 16.2 days, or late, 231 ± 58.9 days), cows were allocated to concentrate treatments representing four levels of rapeseed oil inclusion, 0 (control), 200, 400 and 600 g oil day?1. Oil inclusion had little effect on milk yield but decreased milk fat content significantly (P < 0.01), with a mean depression of 0.40% at the highest level of oil inclusion. The content of milk protein also decreased with increasing addition of oil, but the decrease was smaller than the milk fat depression and was not statistically significant. Increasing the level of rapeseed oil in the diet to 600 g oil day?1 resulted in linear changes in milk fat and protein concentrations which were described by regression equations. For each 100 g of rapeseed oil added to the diet, milk fat content decreased by 0.068% in mid‐lactation cows and 0.061% in late‐lactation cows, while protein content decreased by 0.026% in mid‐lactation cows and 0.028% in late‐lactation cows. Total unsaturated fatty acid content of milk fat also increased in a linear fashion with increased level of oil addition, from 345.7 g kg?1 total fatty acids in control milk fat to 459.3 g kg?1 total fatty acids at 600 g oil day?1, while total saturated fatty acids decreased in the same milk fats from 640.7 to 522.2 g kg?1 total fatty acids. These changes were reflected in lower solid fat contents (SFC) in the milk fat at the lower temperatures of measurement, eg 41% SFC at 5 °C at the highest level of oil inclusion compared with 52% in the control milk fat. However, SFC at 20 °C showed little difference with increasing level of dietary oil addition, an important factor in maintaining product integrity at room temperatures. The relatively high content of the monounsaturated fatty acid C18:1 (345.5 g kg?1 total fatty acids at 600 g oil day?1) and low content of polyunsaturated fatty acids (total C18:2 and C18:3 <40 g kg?1 total fatty acids at 600 g oil day?1) ensured that the oxidative stability of the treatment and control milk fats did not differ significantly. Stage of lactation had an unexplained effect of consistent magnitude on milk fat composition throughout the trial period, with late‐lactation animals producing milk fats containing a significantly (P < 0.001) higher proportion of unsaturated fatty acids than the mid‐lactation animals. Changes in the proportions of unsaturated fatty acids in milk fat, as reflected by changes in iodine value, were established within 2 weeks of the trial commencing and persisted over the 20 weeks of the trial duration. No adverse effect on animal health from this type of dietary manipulation was identified. Copyright © 2004 Society of Chemical Industry 相似文献
11.
《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(2):234-243
Two microbiological kits based on Bacillus stearothermophilus (Eclipse 50® and Premi®Test) have been evaluated and validated according to the European guideline for the validation of screening methods (January 2010) and in relation to the concentrations recommended by the EU-RL in 2007. Both tests are robust, a fast method and easy to implement. Both tests are applicable to a very large variety of honeys from different floral and geographical origins (rosemary, lavender, scrub, heath, alder, forest, lemon, acacia, chestnut, raspberry, mountain and flowers) as well as honey of different colours (from blank honey to brown honey, including yellow and orange honey). A satisfactory false-positive rate of 5% was obtained for the Eclipse 50® test. The observed detection capabilities CCβ of the Eclipse 50® kit were: chlortetracycline (>75?µg?kg?1), oxytetracycline (≤200?µg?kg?1), tetracycline (>100?µg?kg?1), cloxacillin (≤40?µg?kg?1), tylosin (≤200?µg?kg?1), desmycosin (>400?µg?kg?1), sulfadiazine (≤300?µg?kg?1), sulfadimethoxine (≤250?µg?kg?1), sulfamerazine (>300?µg?kg?1), sulfamethazine (>1000?µg?kg?1), sulfamethizole (>75?µg?kg?1), sulfamethoxazole (≤25?µg?kg?1), sulfanilamide (?1000?µg?kg?1), sulfaquinoxaline (>75?µg?kg?1), sulfathiazole (≤250?µg?kg?1) and lincomycin (>1500?µg?kg?1). These levels were all higher than the recommended concentrations where they exist. Due to its lack of sensitivity, it cannot be recommended for reliable routine use. The observed CCβ of the Premi®Test kit were: chlortetracycline (10?µg?kg?1), oxytetracycline (>10?µg?kg?1), tetracycline (≤10?µg?kg?1), cloxacillin (≤5?µg?kg?1), tylosin (≤10?µg?kg?1), desmycosin (≤15?µg?kg?1), sulfadiazine (≤25?µg?kg?1), sulfadimethoxine (≤25?µg?kg?1), sulfamerazine (≤25?µg?kg?1), sulfamethazine (≤25?µg?kg?1), sulfamethizole (≤25?µg?kg?1), sulfamethoxazole (≤10?µg?kg?1), sulfanilamide (≤25?µg?kg?1), sulfaquinoxaline (≤10?µg?kg?1), sulfathiazole (25?µg?kg?1) and lincomycin (≤25?µg?kg?1). The Premi®Test kit could be recommended for reliable use in routine control due to its low detection capabilities (except for aminoglycosides), but the disadvantage is a high false-positive rate of 14%. 相似文献
12.
Simn J Tllez‐Luis Rocío M Uresti Jos A Ramírez Manuel Vzquez 《Journal of the science of food and agriculture》2002,82(9):953-959
Low‐salt restructured silver carp products were obtained using mechanically deboned fish meat from filleting wastes of silver carp (Hypophthalmichthys molitrix). The additives used were NaCl at three levels (0 (control), 10 and 20 g kg?1) and microbial transglutaminase (MTGase) also at three levels (0 (control), 3 and 6 g kg?1). The fish meat was massaged with the additives at <15 °C for 1 h. The massaged fish paste was then packed into steel stainless tubes and cooked at 40 °C for 30 min followed by 90 °C for 15 min. Changes in mechanical properties (texture profile analysis and punch test), solubility, electrophoretic profile and expressible water were evaluated. Hardness was in the range from 26.3 to 52.4 N, cohesiveness varied from 0.185 to 0.318 and springiness varied from 0.418 to 0.768. Increasing the amount of both additives improved the mechanical and functional properties of the restructured silver carp products. MTGase activity was associated with a decrease in protein solubility and a decrease in the myosin band (SDS‐PAGE). Increasing NaCl decreased the amount of expressible water. The results indicated that it is feasible to obtain low‐salt restructured silver carp products with improved mechanical and good functional properties using 3 g kg?1 MTGase and 10 g kg?1 NaCl. © 2002 Society of Chemical Industry 相似文献
13.
Matthias Schreiner Howard W Hulan Ebrahim Razzazi‐Fazeli Josef Bhm Renata G Moreira 《Journal of the science of food and agriculture》2005,85(2):219-226
One hundred and sixty‐eight 1‐day‐old Cobb broiler chickens were randomly assigned to 12 broiler cages to determine the dietary effect of different sources of oils rich in long‐chain omega‐3 polyunsaturated fatty acids (LCω3PUFA). The following oils were added to the feed at a concentration of 12.5 g kg?1: a highly refined seal blubber oil (SBO) containing 225 g kg?1 LCω3PUFA; a fish oil (FO) concentrate containing >800 g kg?1 LCω3PUFA in the form of triglycerides; and an FO concentrate containing >600 g kg?1 LCω3PUFA in the form of ethyl esters. Fatty acid profiles of the breast and thigh meat were measured in order to determine the deposition of LCω3PUFA into the body tissues, whilst fatty acid profiles of the liver and the portal blood were taken in order to deduce consequences of the different ester forms on the absorption process. A triangular sensory evaluation was performed on the breast meat. The levels of LCω3PUFA in all tissues and the portal blood reflected the concentrations of LCω3PUFA in the diets. The sensory properties of the breast meat were negatively influenced by ethyl ester supplementation only. Copyright © 2004 Society of Chemical Industry 相似文献
14.
Yesim Ozogul Gulsun Ozyurt Esmeray Kuley Boga 《Journal of the science of food and agriculture》2009,89(9):1481-1489
BACKGROUND: The effects of rosemary extract on the fatty acid profile of sea bream fillets cooked by different methods (oven baking, grilling and pan frying) as well as the effects of different reheating methods (microwave and conventional oven) on the fatty acid composition of fish after frozen storage for 4 months were investigated. RESULTS: The proportion of saturated fatty acids increased only slightly in fried samples but significantly in oven‐baked and grilled samples, while the proportion of polyunsaturated fatty acids (PUFAs) increased significantly in fried samples but only slightly in oven‐baked and grilled samples. The proportion of monounsaturated fatty acids remained relatively constant after cooking. Of the fatty acids analysed, the most significant increases (P < 0.05) were observed in C18:1n‐9 and C18:2n‐6 and the most significant decreases (P < 0.05) in C14:0, C16:1, C20:5n‐3 and C22:6n‐3. Although sea bream fillets fried in sunflower oil showed an increase in PUFAs, the lowest eicosapentaenoic and docosahexaenoic acid contents were found in fried samples. CONCLUSION: Sea bream fillets treated with rosemary extract showed slower oxidation than untreated fish. Neither conventional nor microwave reheating after frozen storage for 4 months had a detrimental effect on the fatty acid profile and its stability. Copyright © 2009 Society of Chemical Industry 相似文献
15.
Effect of tea polyphenols on microbiological and biochemical quality of Collichthys fish ball 总被引:1,自引:0,他引:1
Yi S Li J Zhu J Lin Y Fu L Chen W Li X 《Journal of the science of food and agriculture》2011,91(9):1591-1597
BACKGROUND: Tea polyphenols (TP), as the most active constituents of tea, are considered natural food additives. This study examined the preservative properties of TP for Collichthys fish ball in well storage. Vacuum‐packed Collichthys fish balls were treated with 0, 0.1, 0.15, 0.20, 0.25, and 0.30 g kg?1 TP and stored at 0 °C for 17 days. RESULTS: Microbiological results were obtained using a biochemical test, API system kit, and 16S rDNA sequence analysis. Results confirmed that the dominant bacteria in Collichthys fish balls are the genera Serratia and Pseudomonas. Total viable counts dropped two orders of magnitude in Collichthys fish balls with 0.25 g kg?1 TP compared with the control. The advantages of total volatile basic nitrogen value, 2‐thiobarbituric acid value and texture value were clearly observed, whereas pH and whiteness value exhibited no significant decrease for the group treated with 0.25 g kg?1 TP. More than 0.25 g kg?1 TP added could retain excellent fish ball characteristics in terms of sensory assessment after 17 days. CONCLUSION: The shelf life of Collichthys fish balls supplemented with tea polyphenols can be prolonged for an additional 6 days in good condition at 0 °C storage. Copyright © 2011 Society of Chemical Industry 相似文献
16.
David G Chamberlain 《Journal of the science of food and agriculture》1989,46(2):129-138
Perennial ryegrass (Lolium perenne L) was ensiled in laboratory silos after addition of glucose or xylose at rates of 0, 25, 35 and 45 g kg?1 fresh grass. In addition, an inoculum of Lactobacillus plantarum, supplying 106 organisms g?1 fresh grass, was applied to all treatments. Silos were opened after 7, 21 and 100 days and the silage was subjected to chemical and microbiological analysis. AH silages were well fermented with pHs between 3·60 and 3·70 and low NH3-N concentrations (<95 g kg?1 total nitrogen) and an absence of butyric acid. Glucose was virtually completely consumed within 21 days but 0·30–0·50 of the xylose doses remained after 100 days. Lactic acid concentrations were not increased by the addition of sugars, but the glucose treatments were associated with very high concentrations of ethanol, 60–100 g kg?1 DM, and the xylose additions produced very high concentrations of acetic acid, 60–135 g kg?1 DM. Most(>0·80) of the glucose that disappeared could be accounted for in ethanol formation but the xylose consumed could be accounted for only if the lactic acid produced in its fermentation was metabolised further to acetic acid; indeed, for the two higher doses of xylose, the concentrations of lactic acid were reduced from the control value of 177 g kg?1 DM to 140 and 120 g kg?1 DM, respectively. The results indicate that the provision of extra sugar, as hexose or pentose, allows yeasts to assume a more prominent role in the fermentation with consequent wasteful fermentation of sugars. Furthermore, the suggestion is that xylose may indirectly, via a stimulation of lactate-assimilating yeasts, encourage further metabolism of lactic acid to acetic acid. 相似文献
17.
Acrylamide in Thai-conventional snacks was analysed by GC/MS with a linear response ranged of 5–50?µg and r 2?>?0.99. The limit of detection (s/n?=?(3) and limit of quantification (s/n?=?10) were 4 and 15?µg?kg?1, respectively, and RSD?<?2%. Acrylamide in 19 food samples ranged from <15?µg?kg?1 to 1.26?mg?kg?1 with highest concentrations in Kanom Jak. Moderate levels (150–500?µg?kg?1) were detected mostly in deep-fried products, especially sweet potato and taro crisps, Kanom Kai Hong, banana fritters, durian chips and spring rolls. Thai-conventional snacks possessed low concentrations (<150?µg?kg?1) including Khao Larm, Pa Tong Koo, sweet banana crisps and deep-fried Chinese wonton. Acrylamide was lowest (<15?µg?kg?1) in fish strips, rice crackers, Hoi Jor and fried fish balls. Dietary habits by 400 tourists indicate a daily intake of acrylamide <150?ng, well below a toxic dose. 相似文献
18.
Seeds of Guizotia abyssinica and wild Guizotia were analysed for oil content and fatty acid composition by multisequential and gas chromatographic methods, respectively. The oil content of G abyssinica ranged from 416 to 436 g kg-1 (weight per kg dry matter of seeds) and that of the wild Guizotia taxa from 214 to 328 g kg-1. Two unsaturated fatty acids (linoleic (54·3–72·8, weight percent of total oil) and oleic (5·4–26·8% of oil by wt) and two saturated fatty acids (palmitic (7·8–10%) and stearic (5·5–8·1%)) were about 91–97% of the fatty acids present. Palmitoleic, linolenic, arachidic, eicosenoic, behenic, erucic and lignoceric acids constituted about 2–3%. An unidentified fatty acid, probably an epoxy form of C: 20 or C: 22, has been found in all the materials and it was 1·1–6·6%. Total saturated and unsaturated fatty acids were about 74–84% and 15–20%, respectively. Differentiation in fatty acid composition between the taxa is too small to be of taxonomic use. It is inferred that when gene transfer is desired hybridisation between the wild and cultivated taxa may not affect the oil quality of the latter and the oils of the wild taxa are possibly safe for human consumption. © 1997 SCI. 相似文献
19.
Adrianus J de Koning Anna Alida Evans 《Journal of the science of food and agriculture》1991,56(4):503-510
Lantern fish of the species Lampanyctodes hectoris were shown to contain phospholipids (10 g kg?1) and non-phosphorylated lipids (140 g kg?1). The phospholipid fraction consisted of phosphatidyl choline (47% of total phospholipids), phosphatidyl ethanolamine (42%), phosphatidyl serine (3%), phosphatidyl inositol (1%), sphingomyelin (4%), lyso-phosphatidyl choline (1%) and cardiolipins (2%). Lantern fish (L hectoris) meals normally contain unacceptably high lipid contents (150 g kg?1 and over); this characteristic was found not to be due to a high phospholipid level in the lantern fish. The major fatty acid of the phospholipids was C22:6n-3 (25% total fatty acids) followed by C16:0 (18%), C18:ln-9 (16%) and C20:5n-3 (8%). This distribution was different from that of the non-phosphorylated lipids where the major fatty acid was C16:0 (21%) followed by C18:ln-9 (19%), C20:5n-3 (11%), C20:l (7%) and C22:6n-3 (7%). The lantern fish press oil and residual meal lipids had fatty acid distributions similar to those of the non-phosphorylated lipids. 相似文献
20.
Damin M Maestri Rene H Fortunato Carlos A Guzmn Mariela M Torres Alicia L Lamarque 《Journal of the science of food and agriculture》2002,82(3):248-251
Seeds of 17 wild leguminous species belonging to the Papilionoideae subfamily were analysed for their proximate, fatty acid and sterol compositions. Centrosema virginianum, Tipuana tipu, Adesmia volckmanni and some species of Desmodium contained high amounts (>300 g kg?1) of protein. Geoffroea decorticans and Clitoria cordobensis were noteworthy for their high oil content (>350 g kg?1). The seed lipids had a high proportion of unsaturated (oleic and linoleic mainly) fatty acids. Linolenic acid had the highest value in Adesmia volckmanni (25.4% of total fatty acids). β‐Sitosterol was the major component of the sterol fraction. Chemical analyses indicated that all species studied are suitable sources of animal feed. © 2002 Society of Chemical Industry 相似文献