首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
With the view of preparing semi-liquid weaning foods of high energy content, the influence of roasting (stationary hot air treatment) and fermentation (with natural and pure culture inocula) on the viscosity of maize-sorghum-soya porridges was investigated. Roasting resulted in porridges of significantly higher viscosity (cooked porridge cooled to 40 °C). Porridges made from the individual ingredients (maize, sorghum, soya) did not show this behaviour. Natural fermentation of mixed ingredients resulted in lower porridge viscosities (cooked porridge cooled to 40 °C, as well as hot-paste peak viscosity) when pH was 5.0–5.5. At lower pH the viscosity of the final porridges increased. Fermentation experiments of individual ingredients inoculated with pure cultures ofLactobacillus plantarum andCandida famata lead to the conclusion that various factors contribute to the effect of fermentation on porridge viscosity. Porridges of minimum viscosity are obtained at pH 5.0–5.5 corresponding with a moderate extent of fermentation. From a consumer safety point of view, it would be preferable to acidify to lower pH values (pH<4.5). If necessary, viscosity adjustments could be made using malted cereals.  相似文献   

2.
Sorghum is a staple crop and a potential dietary source of carotenoids in semi-arid regions of Africa, but information on the bioavailability of these pigments is limited. This study aimed at exploring the effects of agronomic manipulation on sorghum carotenoid contents at selected stages of kernel development and maturation and assessing carotenoid bioaccessibility from matured yellow-endosperm sorghum varieties (P88 and P1222), by comparing porridge made from sorghum whole and decorticated milled grains. Carotenoid content of sorghum milled fractions ranged from 2.90 to 7.22 mg/kg in P88 unbagged decorticated flour, at 50 and 30 days after half bloom (DAHB) respectively, to 9.87-13.69 mg/kg in bagged decorticated bran fractions in P88, at 50 and 30 DAHB respectively. Maize milled fractions were significantly (P < 0.05) higher in carotenoid content than all sorghum products. Bagging increased sorghum carotenoid content by 8-184% vs. unbagged panicles. Carotenoid bioaccessibility was generally higher from sorghum (63-81%) compared to maize (45-47%). Micellarization of xanthophylls (75%) was more efficient than carotenes (52%) in sorghum, while they were similar in maize (40-49%). These results suggest that the higher bioaccessibility of sorghum carotenoids combined with efforts to enhance sorghum carotenoid content may allow for sorghum to provide similar levels of bioaccessible carotenoid pigments as common yellow maize.  相似文献   

3.
Iron availability and degradation of (1→3,1→4)-β-d-glucan (β-glucan) in three whole grain porridges made from two optimised barley malts and unprocessed barley were studied in a dynamic gastrointestinal model. The malting processes, with steeping at 15 or 48 °C with lactic acid (LA), enabled a complete reduction of phytate by subsequent soaking of ground malt, still with well preserved β-glucan. Iron dialysability and iron uptake by Caco-2 cells were higher in phytate reduced porridges, compared to the reference porridge. During simulated digestion, the extractability of β-glucan increased and the Calcofluor average molecular weight decreased for all porridges, indicating a gradual degradation during passage through the model. The degradation rate, however, appeared lower in porridge prepared from malted barley steeped at 48 °C with LA. The gastrointestinal model ranked iron availability according to human absorption data and showed high repeatability when evaluating changes in β-glucan. The results indicate the potential for using high temperature steeping with LA to yield improved iron availability combined with reduced degradation of β-glucan in the small intestine, maintaining the beneficial properties of barley.  相似文献   

4.
Co-delivery of edible proteins with health-protective fruit (muscadine grape) and vegetable (kale) phytoactive compounds was accomplished in a biofortified ingredient for use in convenient, portable food formulations. Polyphenolics were concentrated (10–42 mg/g range) in dry muscadine-protein matrices. Kale-fortified protein matrices also captured polyphenolics (8 mg/g), carotenoids (69 μg/g) and glucosinolates (7 μmol/g). Neither total phenolics nor glucosinolates were significantly diminished even after long term (6 months) storage at 4, 20, or 37 °C, whereas carotenoids degraded over time, particularly at higher temperatures. Dry biofortified phytoactive-protein ingredients allowed delivery of immunoprotective compounds from fruits and vegetables in a stable, lightweight matrix.  相似文献   

5.
Sixty-five Solanum tuberosum group Andigena, Phureja and Stenotomum genotypes from an initial population of 1,500 were analyzed for phenylpropanoids, carotenoids, and antioxidant capacity. Total phenolic content ranged from 3 to 49 mg g?1 DW, total carotenoids from 4.1 to 154 μg/g DW, anthocyanins from 0.27 to 34 mg g?1 DW and antioxidant capacity from 60 to 1,767 μmol TE/g DW. HPLC analysis of phenolic extracts revealed that 5-O-chlorogenic acid (5CGA) was the most abundant polyphenol in all genotypes. Ten genotypes were independently grown out for more in-depth phytonutrient analysis. The Phureja genotypes RN 27.01 had the highest polyphenol, anthocyanin and antioxidant content, while RN 39.05 had the highest carotenoid content. The tuber percentage dry matter varied markedly among the ten genotypes, influencing the phytonutrient values when expressed on a dry weight basis. Chlorogenic acid concentrations ranged from 1.7 to 29.4 mg g?1 DW and kaempferol-3-rutinose was present up to 3 mg g?1 DW. Petunidin-3-O-coum-rutinoside-5-O-glu or pelargonidin-3-O-coum-rutinoside-5-O-glu were the most abundant anthocyanins. The principal carotenoids were lutein, zeaxanthin, violaxanthin, and antheraxanthin, but no one carotenoid was predominant in all genotypes. These findings further support utilization of Phureja group germplasm for phytonutrient enhancement efforts.  相似文献   

6.
The potential use of quality protein transgenic maize (genetically modified maize with the cDNA of amarantin) for preparation of flour and tortillas through an extrusion lime cooking process was investigated. Tortillas from extruded transgenic maize flour had similar physicochemical and sensory properties than those from the commercial brand MASECA™; however, the former had the highest (P < 0.05) protein content (12.91 vs 8.93%, db), essential amino acids content, calculated protein efficiency ratio (C-PER; 2.27 vs 0.90) and protein digestibility corrected amino acid score (PDCAAS; 55.54 vs 30.18%) and therefore they were nutritionally better. The use of transgenic maize for flour and tortilla preparation through an extrusion lime cooking process may have a positive impact on the nutritional status of people from countries where maize is the basic staple food. It also represents an alternative process to nixtamalization that requires little energy and water, it does not generate wastewater, and all components of the maize kernel are retained.  相似文献   

7.
Fruits with red and orange flesh of the columnar cactus pitaya (Stenocereus pruinosus) were studied to evaluate physical characteristics, total soluble solids, betalains and soluble phenols content, and antioxidant activity. Fruits had, in average, weight of 179.0 g, 9.8 °Brix, 9.4 % carbohydrates, 1.25 % protein, 0.11 % ethereal extract, 0.60 % crude fiber, and 0.62 % ash. Also, fruits resulted rich in Fe (22.8–27.8 mg/kg). Hue angle and contents of betacyanins, betaxanthins (μg/g dry sample), and total soluble phenols (mg GAE/g fresh sample) were 19.8°, 2860.0, 3210.0, and 1.6 in the red material, and 28.9°, 470.0, 2670.0, and 1.2, respectively, in the orange fruit. The antioxidant capacity was higher in the red material, since the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) technique reported 1090.6 and 735.4 μmol of Trolox equivalents/g fresh flesh in red and orange fruits, respectively, while the oxygen radical absorbance capacity (ORAC) assay reported 7.84 and 5.16 μmol of Trolox equivalents/g fresh flesh, respectively. The chromatographic profile showed five betalains in red fruits, but only four of them were observed in those orange fleshed.  相似文献   

8.
Nixtamalization process is the first step to obtain maize based products, like tortillas; however, in both the traditional and commercial processes, white grain is generally preferred. Creole maize races, mainly pigmented varieties, have increasingly attention since these are rich in anthocyanins and carotenoids. The aim of this investigation was to evaluate the antioxidant and antimutagenic activity of rich anthocyanins and carotenoids extracts from creole maize races before (grain) and after (masa and tortilla) the nixtamalization process. Most anthocyanins and carotenoids were lost during nixtamalization. Before nixtamalization, blue and red genotypes contained either higher antioxidant capacity and anthocyanin contents (963?±?10.0 and 212.36?±?0.36 mg of cyanidin-3-glucoside eq/100 g, respectively) than the white and yellow genotypes. However, the highest carotenoid levels were displayed by red grains (1.01?±?0.07 to 1.14?±?0.08 μg of β-carotene eq/g extract). Anthocyanins losses were observed when the blue grains were processed into masa (83 %) and tortillas (64 %). Anthocyanins content correlated with antiradical activity (r?=?0.57) and with 2-aminoanthracene -induced mutagenicity inhibition on TA98 and TA100 (r?=??0.62 and r?=??0.44, respectively). For white grains, nixtamalization also reduced carotenoids (53 to 56 %), but not antioxidant activity and 2-Aa-induced mutagenicity. Throughout the nixtamalization process steps, all the extracts showed antimutagenic activity against 2-aminoanthracene—induced mutagenicity (23 to 90 %), displaying higher potential to inhibit base changes mutations than frameshift mutations in the genome of the tasted microorganism (TA100 and TA98, respectively). The results suggest that even though there were pigment losses, creole maize pigments show antioxidant and antimutagenic activities after nixtamalization process.  相似文献   

9.
Four Beninese cultivars (two local ecotypes and two new cultivars) were tested for their ability to produce ogi. The two local ecotypes, having friable and floury to medium vitreous kernels, gave a higher yield of ogi (10% more) than the improved cultivars that had coherent and vitreous kernels. They also gave slightly more viscous ogi porridges. Whatever the storage conditions (20 to 35°C, 3 to 15 d), a hetero-lactic fermentation generated two characteristic products: lactic acid and ethanol. However, the fermentation process was more intense and more rapid at 35°C giving a peak in acidity at the end of the first week, then a decrease during the second week. In parallel, ori porridge viscosity increased during the second week of fermentation.  相似文献   

10.
Potato has a defined complement of metabolites that contribute to the human diet. Among these are the carotenoids and anthocyanins. Carotenoids are found in all potatoes in the flesh. White-fleshed varieties have 50 to 100 μg per 100 g fresh weight (FW), while moderately yellow-fleshed varieties will generally possess from 100 to 350 μg per 100 g FW. The more intensely yellow-fleshed genotypes, which may look orange, at the higher extremes are at levels above 1,000 μg per 100 g FW. The highest level published is 2,600 μg per 100 g FW in diploid germplasm derived from South American Papa Amarilla cultivars. Potato generally has predominantly lutein, a xanthophyll which is also found in the human retina, and must be obtained in the diet. The genotypes with extremely high levels of total carotenoids have zeaxanthin, an isomer of lutein, which is also present in the human retina. Anthocyanins are present in red- or purple-skinned and fleshed varieties. Total anthocyanins range from 1.5 mg to 48 mg per 100 g FW in a solidly pigmented purple-skinned, purple-fleshed breeding line. The degree of pigmentation in the flesh appears to be under polygenic control. Anthocyanins are potent antioxidants and anti-inflammatory substances. The level of total anthocyanins is correlated with antioxidant level (r?=?0.94, P?<?0.001). Several methods of cooking interacted with genotypes in the antioxidant level remaining after cooking compared to raw potatoes. No method of cooking completely eliminated antioxidant activity, while boiling appeared to increase it compared to raw potato in the case of the most highly pigmented clone.  相似文献   

11.
The objective of this study was to determine the best combination of extrusion process variables for the production of whole quality protein maize (EQPMF) and common bean (ECBF) flours to prepare a high antioxidant activity mixture (EQPMF + ECBF) suitable to produce a nutraceutical beverage with high acceptability elaborated with a traditional Mexican formulation. Processing conditions were obtained from a factorial combination of barrel temperature (BT?=?120–170 °C) and screw speed (SS?=?120–200 rpm). Response surface methodology was applied to obtain maximum values for antioxidant activity (A ox A) of the flour mixture (EQPMF + ECBF) and acceptability (A) of the nutraceutical beverage. The best combinations of extrusion process variables for EQPMF and ECBF to prepare an optimized mixture (60%EQPMF?+?40%ECBF) were BT?=?98 °C/SS?=?218 rpm and BT?=?105 °C/SS?=?83 rpm, respectively. The optimized mixture had A ox A?=?14,320 μmol Trolox equivalent (TE)/100 g sample dry weight (dw) and a calculated protein efficiency ratio (C-PER) of 2.17. A 200 ml portion of a beverage prepared with 25 g of the optimized flour mixture had A ox A?=?3,222 μmol TE, and A?=?89 (level of satisfaction “I like it extremely”). This nutraceutical beverage could be used as an alternative to beverages with low nutritional/nutraceutical value, such as those prepared with water, simple sugars, artificial flavoring and colorants, which are widely offered in the market.  相似文献   

12.
The indigenous pitanga (Eugenia uniflora L.) is now marketed and commercially processed in Brazil. In the present work, the carotenoids of the pitanga fruit from two states and at two stages of ripening, as well as of processed pitanga products (frozen pulp and juice, the brands being designated as A, B and C) commercialized in Campinas, São Paulo, were determined by HPLC. As compared to ripe pitanga from Medianeira, Paraná, those from Campinas had significantly higher (all-E)-lycopene (14.0 vs. 71.1 μg/g), (13Z)-lycopene (1.1 vs. 5.0 μg/g) and (all-E)-γ-carotene (1.6 vs. 3.8 μg/g) levels. Significant increases in most of the carotenoids occurred from the partially ripe to the ripe fruits, with (all-E)-lycopene doubling its concentration in fruits from both states. Pitanga was found to be one of the richest fruit sources of carotenoids, particularly lycopene, but the processed products had much lower lycopene content. The mean (all-E)-lycopene concentration was 16.6 μg/g for frozen pulp brand A, 23.0 μg/g for bottled juice brand B and 25.6 μg/g for bottled juice brand C. Optimization of processing is therefore needed to guarantee better retention of this important carotenoid.  相似文献   

13.
The chemical, sensory and rheological properties of porridges made from blends of sprouted sorghum, bambara groundnuts and fermented sweet potatoes were examined. Sorghum and bambara groundnuts were sprouted for 48 h while sweet potatoes were fermented for the same period. Blends were formulated from the processed ingredients in the ratio of 60:40:0, 57:42:1, 55:44:1 and 52:46:2 (protein basis) of sorghum, bambara groundnuts and sweet potatoes. Porridges were prepared from the composite flours and the traditional sorghum complementary food. Standard assay methods were used to evaluate the flours for nutrient composition. The porridges were also tested for sensory properties and viscosity. Processing increased the levels of most of the nutrients evaluated. Relative to the sorghum traditional complementary food, thecomposite flours had higher levels of lipids, protein, ash, crude fiber and minerals (p<0.05). The porridges from the composite flours were generally liked slightly by the panelists and were about seven times less viscous than the porridge from the traditional sorghum complementary food. Use of the composite flours, particularly the 52:46:2 blend, as a traditional complementary food should be encouraged in Nigeria especially with the increasing cost of commercial complementary foods.  相似文献   

14.
Seeds of Mucuna pruriens (L.) DC. (Fabaceae) were analyzed for protein composition of protein bodies isolated from cotyledons. Protein bodies were successfully separated by Lympholyte and those of dry seeds, observed by scanning electron microscope, were elliptical or spherical in shape with a diameter of 5–12 μm. Protein content in dry seed protein bodies was 10.6 mg/g dry weight. Globulin was the largest protein fraction isolated (62.5 %), followed by albumin (18.3 %), glutelin (15.8 %) and prolamin (3.4 %). The prolamin fraction and high glutelin content are uncommon in legumes. SDS-PAGE of albumins, globulins, prolamins and glutelins provided different band numbers and molecular weights under reducing and non reducing conditions and suggested that the albumin fraction is rich in disulphide bonds.  相似文献   

15.
The effects of cowpea and amino acid supplementation on the protein quality and chemical characteristics of a maize-based West African traditional weaning food were studied. Process optimization for improved nutritive value was also determined. Supplementation of the traditional weaning food with cowpea increased the lysine, tryptophan and threonine content while the sulphur-amino acids decreased with increasing levels of cowpea. Further supplementation of 70:30 maize/cowpea blends with lysine, threonine or methionine did not significantly improve (p>0.05) protein quality in terms of the biological value (BV) and net protein utilization (NPU), although significant increases in the protein scores were noted. However, considerable improvements in the BV and NPU were recorded in blends fortified with either tryptophan alone or a combination of lysine, tryptophan, methionine and threonine. Cooking whole cowpea seeds for 45 min before incorporating in the blend formulation also significantly improved (p<0.05) the protein quality of maize/cowpea blends. The BV and NPU of blends containing 30% pre-cooked cowpea increased from 52 to 76% and 50 to 71% respectively compared to pure maize porridge. The protein content increased from 10 to 14% and the utilizable proteins more than doubled. The weight increase of experimental rats fed with these blends was comparable to that of rats on casein diet. A 30% supplementation of the maize-based weaning food with cowpea therefore greatly enhances the nutritive value especially when the cowpea is pre-cooked for 45 min. Use of chemical scores alone for such blends cannot be a reliable index of blend quality.  相似文献   

16.
The process of in vivo esterification of xanthophylls has proven to be an important part of the post-carotenogenesis metabolism which mediates their accumulation in plants. The biochemical characterization of this process is therefore necessary for obtaining new and improved crop varieties with higher carotenoid contents. This study investigates the impact of postharvest storage conditions on carotenoid composition, with special attention to the esterified pigments (monoesters, diesters and their regioisomers), in durum wheat and tritordeum, a novel cereal with remarkable carotenoid content. For tritordeum grains, the total carotenoid content decreased during the storage period in a clear temperature-dependent manner. On the contrary, carotenoid metabolism in durum wheat was very much dependent on the physiological adaptation of the grains to the imposed conditions. Interestingly, when thermal conditions were more intense (37 °C), a higher carotenoid retention was observed for tritordeum, and was directly related to the de novo esterification of the lutein induced by temperature. The profile of lutein monoester regioisomers was constant during storage, indicating that the regioisomeric selectivity of the XAT enzymes was not altered by temperature. These data can be useful for optimizing the storage conditions of grains favoring a greater contribution of carotenoids from these staple foods.  相似文献   

17.
采用溶液培养方法,研究茉莉酸对玉米幼苗叶片抗镉性的影响。结果表明,镉胁迫显著提高玉米叶片丙二醛(MDA)、H_2O_2含量和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽转移酶(GST)、谷胱甘肽过氧化物酶(GPX)活性,降低过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)和谷胱甘肽还原酶(GR)活性,降低叶绿素a、叶绿素b和类胡萝卜素含量及生物量。与单独镉胁迫相比,外源茉莉酸处理可显著提高镉胁迫下叶片CAT、POD、APX和GR活性,显著提高叶绿素a、叶绿素b和类胡萝卜素含量及生物量,显著降低镉胁迫下叶片MDA和H_2O_2含量,从而缓解其造成的伤害。结果表明,外源茉莉酸可明显提高玉米幼苗叶片的抗氧化能力和光合色素含量,从而增加生物量的积累,缓解镉胁迫造成的伤害。  相似文献   

18.
The objective of this research was to investigate the effects of different ingredients (reducing sugars, leavening agents, citric acid), processing conditions (feed moisture content, exit die temperature), and extrusion cooking methods (with/without CO2 injection) on furfural and 5-hydroxymethylfurfural (HMF) formation in corn-based extrudates. The decrease in furfural levels was 16% upon addition of sodium-bicarbonate, while the increase was 12% upon addition of ammonium-bicarbonate for extrudates produced at 150 °C and feed moisture content of 22%. The furfural concentration of extrudates produced at 150 °C and feed moisture content of 22% without leavening agents was 810 μg/100 g and increased to 11,901 μg/100 g upon citric acid addition (about a 15-fold increase). Furthermore, both low feed moisture and high exit die temperature had promoting effects on furfural and HMF contents. The CO2 injection method did not have considerable effect on furfural and HMF levels of the extrudates; however, it positively affected the physical properties of extrudates.  相似文献   

19.
High carotenoid potato may have particular value for human health due to the antioxidant properties and the therapeutic value for eye health in patients at risk for macular degeneration. Carotenoid concentrations were determined among the progeny of a cross between two high carotenoid lines derived from diploidPapa Amarilla germplasm from South America. The total carotenoid content ranged from 82 to 2686 µg / 100 g fresh weight (FW). The higher values greatly exceeded the mid-parent value of the cross. An index for yellow tuber flesh color was determined for a subset of the progeny. A cleaved amplified polymorphic sequence (CAPS) assay was developed to distinguish the alleles of beta-carotene hydroxylase (bch) in the two high-carotenoid parents. Abch allele (denoted B) common to the high carotenoid parents co-segregated with yellow flesh in the progeny of a white-flesh x yellow-flesh cross, makingbch an excellent candidate for the classicalY locus, required for yellow tuber flesh. The same allele was also present in all other yellow-fleshed potato clones tested. Genotype atbch explained a portion of the variation of total carotenoid (R2=0.42). Clones homozygous for the B allele (BB) contained, on average, slightly more carotenoid than heterozygous Bb clones, which in turn had much more carotenoid than homozygous bb clones, suggesting a partially dominant gene model. Similarly, bb flesh was significantly less yellow than Bb and BB, the latter two being quite close. Total carotenoid varied considerably between progeny in the Bb and BB genotype categories, suggesting that variation at one or more additional loci have a significant effect on total carotenoid levels. Since the total carotenoid levels in manyPapa Amarilla cultivars and progeny are much higher than those in white- and yellow-fleshed tetraploid cultivars, it may be possible to breed for high carotenoid values in tetraploid germplasm by introducing one or more genes derived fromPapa Amarilla germplasm.  相似文献   

20.
Raspberries contain flavonoid antioxidants whose relative concentrations may vary between the juice, pulp, and seed fractions. Oxygen radical absorbance capacity (ORAC), total anthocyanin content, and berry color were determined for six cultivars of primocane raspberries grown in a dry climate (Utah, USA). Significant ORAC differences were found between juice (18.4?±?0.39 μmol TE/g), pulp (24.45?±?0.43), and seeds (273.27?±?11.15) with all Utah cultivars combined. A significantly higher concentration of anthocyanins was present in Utah raspberry juice (20.86?±?0.35 mg cyanidin-3-glucoside eq./100 g), compared to pulp (13.96?±?0.35). Anthocyanin content of juice and pulp were significantly positively correlated with dark color (L*). This is the first report of fractional differences in dry climate raspberries, and has implications for the juice and supplement industries.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号