不同品种小米粉体外消化性的测定与分析

用α–淀粉酶和淀粉糖化酶酶解消化小米粉样品,采用3,5–二硝基水杨酸比色法(DNS)测定水解过程中产生的葡萄糖,对不同品种小米粉的体外消化特性进行比较,分析淀粉水解速率,快消化淀粉(RDS)、慢消化淀粉(SDS)和抗性淀粉(RS)含量,以及RDS、SDS、RS含量与直链淀粉含量的相关性。试验结果表明:复1、济12、市售的直链淀粉含量分别为1.96%、30.58%、35.58%;快消化淀粉(RDS)含量分别为87.18%、83.41%、80.73%;慢消化淀粉(SDS)含量分别为4.128 9%、8.72%、12.97%;抗性淀粉(RS)含量分别为8.69%、7.87%、6.31%。     

加工方法对红小豆碳水化合物消化速度的影响

运用体外模拟消化方法探讨了不同加工方法对红小豆中碳水化合物的消化速度和淀粉组分中快速消化淀粉(RDS)、慢速消化淀粉(SDS)和抗性淀粉(RS)含量的影响。结果表明,烹调压力和颗粒大小对红小豆中淀粉消化率及淀粉组分有较大影响。高压烹调水解率高于常压烹调,烹调前粉碎处理显著提高RDS和淀粉水解指数(SDI),但烹调压力对豆粉的消化速度指标无影响;煮熟的豆在冷藏前后碳水化合物水解率的差异不显著。     

蒸煮条件及回生处理对方便米饭消化特性的影响

考察蒸煮方式及回生处理对方便米饭体外消化率的影响。实验利用不同蒸煮条件及回生时间处理低直链淀粉含量和高直链淀粉含量的不同品种大米,制备得到具有不同性质的方便米饭,并研究了方便米饭快消化淀粉(RDS)、慢消化淀粉(SDS)和抗性淀粉(RS)的含量差异及其体外消化率。结果表明,相对于电饭锅蒸煮,采用常规方式蒸煮,即控制米水比为1∶1,86℃蒸煮28 min制备的方便米饭RDS含量得到极大的降低,SDS含量明显的升高(P0.05)。回生处理可以显著的降低方便米饭RDS含量。与此同时,实验发现低直链淀粉含量品种的米饭含有较低的RDS含量、较高的SDS和RS含量,高直链淀粉含量品种的米饭则含有较低的SDS和较高的RS含量。通过控制蒸煮和回生条件,可以得到淀粉消化率低的方便米饭,对肥胖及高血糖人群健康有积极作用。     

韧化处理对3种晶型淀粉消化特性的影响

比较玉米淀粉(A型)、马铃薯淀粉(B型)和锥栗淀粉(C型)韧化处理前后的颗粒形貌、结晶特性和热特性变化,探究韧化处理对3种晶型淀粉消化特性的作用机理。SEM图片显示,韧化处理后玉米淀粉表面出现凹坑,马铃薯淀粉表面出现少许裂痕,锥栗淀粉表面变得光滑,褶皱消失;XRD和FTIR分析表明,3种淀粉经韧化后晶型未有改变,但结晶度均显著提高,分子短程有序性增加,晶体结构更趋稳定;DSC分析表明,韧化处理后3种晶型淀粉的糊化温度显著升高,热焓值无显著变化;韧化处理对不同晶型淀粉消化特性的影响存在差异,3种淀粉经韧化后RS含量均显著增加,水解指数HI和血糖指数GI显著降低;玉米淀粉韧化后RDS含量显著增加,SDS含量显著减少,水解平衡浓度由84.81%降至76.79%;马铃薯淀粉中SDS和RDS含量均显著减少,水解平衡浓度由30.59%降至21.84%;韧化处理对锥栗淀粉的RS、SDS、RDS含量及水解平衡浓度变化影响较小。     

糯米粉储藏过程中的消化性能

研究糯米淀粉的消化性能,与玉米淀粉、马铃薯淀粉和豌豆淀粉进行对比,研究发现,经过糊化后的淀粉比天然淀粉中的快消化淀粉(RDS)含量增加50%左右,而原先品种不同淀粉的慢消化淀粉(SDS)和抗性淀粉(RS)含量均会减少至10%左右,并且基本没有差异性。糊化后,糯米淀粉的RDS上升到最大,说明淀粉糊化后的消化性能和支链淀粉的含量呈负相关的关系。在短期储藏中,多数淀粉体系中的SDS和RS含量上升幅度均在5%左右,而RDS的含量下降幅度在10%。但糯米淀粉较特殊,因为在储藏早期影响淀粉消化性能的主要是直链淀粉,糯米淀粉主要含的是支链淀粉,支链淀粉的重结晶发生缓慢。所以,在储藏早期其对糯米淀粉消化性能的影响非常小,RDS、SDS和RS含量基本没有变化。     

红小豆-粳米混合食物的碳水化合物体外消化速度研究

碳水化合物的消化速度直接影响着淀粉类主食的餐后血糖反应,因此可利用碳水化合物的体外模拟消化预测淀粉类主食品的血糖反应。用胰酶模拟小肠消化测定了几种烹调方法下红豆-粳米混合膳食中碳水化合物的消化速度,并探讨了其中快速消化淀粉(RDS)、慢速消化淀粉(SDS)和抗性淀粉(RS)相对含量的变化,结果表明:高压烹调显著提高了整豆-粳米混合食物的水解率和RDS含量,但豆粉-米混合食物在不同烹调压力下的差异不显著。整豆和大米分别烹调后再混合的食物与豆谷共同烹调食物相比,抗性淀粉的含量较高,且淀粉消化指数较低。红小豆-粳米混合食物的消化速度与精白粳米的消化速度呈显著性差异(p<0.05)。烹调方法对食物中碳水化合物的消化速度有很大影响。血糖调节异常的人群适合在主食原料中添加整豆类食物,以帮助稳定餐后血糖反应。     

压热法制备抗消化红芸豆粉

采用压热法处理红芸豆粉，以抗性淀粉含量为指标，在单因素试验的基础上通过响应面法优化抗消化红芸豆粉的制备工艺。结果表明：最佳工艺条件为红芸豆粉悬浊液质量分数19%、压热温度125℃、压热时间35 min、冷藏时间25 h,在此条件下红芸豆中抗性淀粉含量为29.82%±0.17%。压热处理能显著增加红芸豆淀粉含量，显著降低红芸豆水分含量，有效降低红芸豆的水解指数(HI)和估计血糖生成指数(eGI)。     

马铃薯淀粉物化特性分析及其对马铃薯热干面品质影响

为研究马铃薯淀粉的物化特性,以马铃薯为试验原料并对其中淀粉进行提取,并探讨不同含量马铃薯淀粉对混粉物化特性以及生鲜马铃薯热干面和干制马铃薯热干面品质的影响。结果表明,马铃薯中淀粉含量为73.80%,马铃薯淀粉中直链淀粉含量为28.23%,支链淀粉含量为71.70%;马铃薯淀粉中快消化淀粉(RDS)、慢消化淀粉(SDS)和抗消化淀粉(RS)含量分别为20.29%、15.03%和64.68%。马铃薯淀粉添加量在60%～70%时,混粉的持水性、吸水膨胀性和粘度值较高;马铃薯淀粉含量为70%～80%时,能较好的改善生鲜马铃薯热干面的蒸煮特性和质构特性;马铃薯淀粉含量在70%时,干制马铃薯热干面的复水特性最好;随着马铃薯热干面中马铃薯淀粉含量的增加,干制热干面更易消化。综上所述,马铃薯淀粉的建议添加量为70%。     

双螺杆挤压对菠萝蜜种子淀粉消化特性及血糖指数的影响

为探究双螺杆挤压对菠萝蜜种子淀粉(JFSS)的消化特性及血糖指数的影响,采用体外消化试验,考察了JFSS经挤压处理前后的消化性与消化动力学变化,并通过水解指数(HI)、血糖指数(GI),预测了菠萝蜜种子淀粉的餐后血糖水平(PPBS)。结果表明,双螺杆挤压增加了快速消化淀粉(RDS)与慢消化淀粉(SDS)含量,提高了平衡浓度(C_∞)、酶解速率(k)、水解指数(HI)、血糖指数(GI)和淀粉消化率,显著降低了抗性淀粉含量(RS)(P<0.05)。在低水分含量下,增加螺杆转速与机筒温度,RDS含量由47.85%增加到58.91%,且k、C_∞、HI、GI值也均呈现增加趋势,而SDS含量、RS含量呈降低趋势。螺杆挤压使菠萝蜜种子淀粉由致密结构转变为疏松多孔的多面体结构。     

不同食用胶体对馒头食用品质及消化特性的影响

该文以优化储藏期内淀粉消化特性,改善食用品质为目的,研究不同食用胶体对馒头淀粉消化特性及食用品质的影响,利用全自动快速食品热量成分检测仪、色差仪、质构仪等分别对添加了不同食用胶体的馒头进行品质分析,并通过体外消化实验对馒头的淀粉组成及体外血糖生成指数（estimated glycemic index,eGI）进行测定。结果表明,在0.3% 当量下,添加5 种食用胶体（黄原胶、瓜尔豆胶、聚丙烯酸钠、海藻酸钠、羧甲基纤维素）均能改善馒头的pH 值和色度值,热量无显著性变化。从淀粉消化特性分析,瓜尔豆胶组相对于其他食用胶体组馒头具有更低的eGI 值。从储藏期内馒头淀粉各组分含量分析,羧甲基纤维素组馒头在4 ℃冷藏条件下储存7 d 后的快消化淀粉（rapidly digestible starches,RDS）含量仍保持较高,抗性淀粉（resistant starch,RS）含量最低,分别为54.02% 和18.75%,拥有更好的消化特性和优秀的感官评分。     

脱皮脱脂杂豆粉的理化与功能特性

以大白芸豆、奶花芸豆、小白芸豆、豇豆、绿豆、红小豆、小扁豆、豌豆8种食用杂豆为实验材料,以大豆为对照,对其脱皮、脱脂后的杂豆粉理化特性和功能特性进行比较分析。结果表明：与脱皮脱脂大豆粉相比,脱皮脱脂杂豆粉的堆积密度和吸水性指数高,水溶性指数、吸水能力、吸油能力低,乳化性、乳化稳定性差异不显著,凝胶能力强,起泡性及起泡稳定性差异显著。不同杂豆粉之间的理化特性与功能特性有差异。脱脂大白芸豆粉的堆积密度小,水溶性指数、吸油性和乳化稳定性高;脱脂小白芸豆粉吸水性、乳化性、起泡性及起泡稳定性强;脱脂豌豆粉凝胶能力和起泡性好,乳化稳定性差。     

Forage intake,meal patterns,and milk production of lactating dairy cows fed grass silage or pea-wheat bi-crop silages

This study investigated the feed intake, milk production, and plasma nutrient status in dairy cows fed inter-cropped pea-wheat (bi-crop) silages comprised of contrasting ratios of pea to wheat. Spring peas (cv. Magnus) and wheat (cv. Axona) sown at either high (75:25) or low (25:75) pea inclusion rates were harvested after 13 (Cut 1) or 15 (Cut 2) wk. Eighteen Holstein-Friesian cows between wk 9 and 10 of lactation were used in a cyclical changeover design with three 28-d periods. Cows were fed the bi-crop silages and 6 kg of concentrates or second-cut grass silage supplemented with 6 (GS6) or 9 (GS9) kg/d of concentrates. Forage intakes were higher when bi-crops were fed (10.3 to 11.4 kg dry matter [DM]/d) than when grass silage was fed (8.6 kg DM/d). Total DM intake was similar among cows fed the bi-crop silages and GS9 diets, but intakes for GS6 were at least 1.7 kg DM/d lower. Increasing the pea inclusion rate increased the crude protein (CP) content of the ration, but it did not enhance forage quality or animal performance. The rate of intake of the different forages was similar, so that the higher intakes of bi-crop silages were associated with more time spent at the feedbunk and an increased number of meals. Diet digestibility ranged from 531 to 650 g/kg, and the highest value was given by the Cut 1 bi-crop silage diet. Milk yield tended to be similar for cows fed the Cut 2 bi-crop and GS9 diets, and these values were at least 1.7 kg higher than those for cows fed on other treatments. Generally, the bi-crop diets resulted in higher milk fat contents and lower polyunsaturated fatty acid contents. Milk protein content was highest for cows fed the GS9 diet. Blood metabolite content was unaffected by treatment except for blood urea nitrogen content, which was higher in cows fed the bi-crop silages, reflecting reduced N-use efficiency with these diets. The study showed that pea-wheat bi-crop silages can be used to replace moderate-quality grass silage in dairy cow rations, but their role as alternatives to high-quality forages requires additional investigation.     

Physical and chemical analyses of pigeonpea (Cajanus cajan) cultivars and F1 crosses

The weight of ‘dhal’ (the edible part of the seed) from 100 whole seeds, and the hull, protein, fat, starch and soluble carbohydrate contents of 12 pigeonpea (Cajanus cajan) cultivars and the F₁ crosses were determined. The mean values for cultivars and the F₁ crosses differed in 100-seed wt, hull content (%) and protein and starch contents. Whereas 100-seed wt showed a high positive correlation with the weight of dhal, its correlation was significantly negative with hull content (%) in cultivars and protein content in the F₁ crosses.     

Evaluating the inclusion of alfalfa hay in diets fed to multigravid Holstein cows in their transition to early lactation

The objectives of this study were to determine the dry matter intake (DMI), urine pH, Ca concentration in blood, Ca output in urine, and frequency of hypocalcemia in pregnant and nonlactating dairy cows consuming diets containing different hays and acidogenic products during the prepartum period. Eighty pregnant and nonlactating Holstein cows approaching their second or greater calving were fed 1 of 4 experimental diets according to a 2 × 2 factorial arrangement of treatments during the prepartum period (21 d before calving). Diets included either grass hay (GH) or alfalfa hay (AH) and calcium chloride (CL) or polyhalite (PO) as the acidogenic products. All diets had a dietary cation-anion difference (DCAD) below −190 mEq/kg of dry matter (DM). Grass hay contained 75 g/kg crude protein, 749 g/kg neutral detergent fiber, 3.6 g/kg Ca, 0.9 g/kg Na, 18.8 g/kg K, 3.8 g/kg Cl, 1.5 g/kg S, and a cation-anion difference equal to 290 mEq/kg of DM. Alfalfa hay contained 196 g/kg crude protein, 456 g/kg neutral detergent fiber, 15.2 g/kg Ca, 1.6 g/kg Na, 25 g/kg K, 7.7 g/kg Cl, 3.2 g/kg S, and a cation-anion difference equal to 292 mEq/kg of DM. Cows consuming GH tended to consume more DM than cows consuming AH (11.6 vs. 10.8 kg/d) but DMI did not differ between acidogenic products. Urine pH decreased below 6.5 for all diets, although cows consuming the GHPO diet had the highest urine pH. The concentration of Ca in plasma decreased substantially around calving but neither hay type nor acidogenic product affected it. Urinary Ca output was lowest for cows consuming the GHPO diet. No associations existed between dietary treatments and the frequencies of normocalcemia and hypocalcemia. Under the conditions of this study, in which alfalfa and grass hays had similar cation-anion differences, we concluded that the inclusion of alfalfa hay in prepartum diets does not necessarily increase the frequency of hypocalcemia. The cation-anion difference of the alfalfa hay, more than the concentration of potassium alone, may be a key determinant of whether alfalfa hay fits in a prepartum feeding program for prepartum dairy cows. Further research should explore this relationship.     

Soybean whole-plant ensiled with chitosan and lactic acid bacteria: Microorganism counts,fermentative profile,and total losses

Chitosan is a biopolymer derived from chitin deacetylation, present in the exoskeleton of crustaceans and insects. Chitosan has been evaluated as rumen modulator and silage additive due to its antimicrobial properties. The objective of this study was to determine the effects of both chitosan and a bacterial additive on microbiological quality, chemical composition, nutrient in vitro degradation, fermentative profile, and total losses of whole-soybean plant silage (SS) harvested at R6 stage. Four treatments in a factorial arrangement were randomly assigned to 40 experimental minisilos as no additives (CON), 8 g/t fresh forage of microbial inoculant (INO; Kera SIL, Kera Nutrição Animal, Bento Gonçalves, Brazil); 5 g/kg of fresh forage chitosan (CHI); and CHI + INO. Microbial inoculant was composed of Lactobacillus plantarum (4.0 × 10¹⁰ cfu/g) and Propionibacterium acidipropionici (2.6 × 10¹⁰ cfu/g). The CHI and INO alone increased counts of lactic bacteria and anaerobic bacteria and decreased counts of mold and yeast in SS. The CHI or INO alone increased in vitro degradation of dry matter, crude protein, and neutral detergent fiber, and decreased nonfiber carbohydrate content of SS. Chitosan increased NH₃-N and lactate concentrations and decreased ethanol concentration in SS. The CHI increased dry matter recovery from SS; INO increased silage aerobic stability. The combination of CHI+INO showed the lowest value of gas losses. In general, the combination of CHI and INO had small positive effects on gas losses of SS; however, both CHI or INO alone improved nutrient in vitro degradation and decreased mold and yeast in SS. Chitosan or INO utilization improves SS quality.     

Effect of maturation on nutrient composition of selected vegetable legumes

Five legume vegetables harvested at the immature green and mature stages were analysed for weight and nutrient composition. In some types the seed weight increased up to seven-fold in the last 10 days of maturation. The protein, fat, carbohydrate and thiamin contents increased on maturation. However, the proportional increase varied widely from 10 to 100 % in the case of protein and carbohydrates. The changes observed in the nutrient composition and weight of vegetable legume seeds in the last 10 days of maturation suggest that it is advantageous to harvest vegetable legumes when mature.     

Partial replacement of corn silage with whole-plant soybean and black oat silages for dairy cows

This study aimed to evaluate the effects of partially replacing corn silage (CS) with whole-plant soybean silage (SS) or black oat silage (OS) on nutrient intake and digestibility, in vitro neutral detergent fiber degradability of silages, feeding behavior, rumen fermentation, and performance of dairy cows. Twenty-four lactating Holstein cows (6 of which were rumen-cannulated) with 32.5 ± 4.92 kg/d milk yield, 150 ± 84.8 days in milk, and 644 ± 79.0 kg of body weight were used in a 3 × 3 Latin square design to evaluate the following treatments: (1) corn silage diet (CSD): using corn silage as the only forage source in the diet [48% dietary dry matter (DM)]; (2) whole-plant soybean silage diet (SSD): SS replacing 16% of corn silage from CSD; and (3) black oat silage diet (OSD): OS replacing 16% of corn silage from CSD. The inclusion of OS and SS decreased intakes of DM, organic matter, and crude protein. Corn silage had the greatest in vivo effective degradability of DM, and SS had the least effective degradability of neutral detergent fiber. The OSD treatment decreased milk and protein yields, whereas SSD increased rumen ammonia nitrogen concentration compared with the other diets. Cows fed OSD exhibited a greater preference for feed with small particles (<4 mm) compared with those fed SSD. Cows fed treatments containing either SS or OS at the expense of CS had increased rumination and chewing activities. Although replacing CS with OS and SS reduced feed intake, SS had no effect on productive performance of dairy cows.     

Nutritive value, fermentation characteristics, and in situ disappearance kinetics of ensiled warm-season legumes and bahiagrass

This study determined the nutritive value, ensiling characteristics, and in situ disappearance kinetics of bahiagrass (Paspalum notatum Flügge ‘Tifton 9’), perennial peanut (Arachis glabrata Benth. ‘Florigraze’), annual peanut [Arachis hypogaea (L.) ‘FL MDR 98’], cowpea [Vigna unguiculata (L.) Walp. ‘Iron clay’], and pigeonpea [Cajanus cajan (L.) Millsp. ‘GA-2’]. All forages were harvested at maturity stages that optimized dry matter (DM) yield and nutritive value. After harvest, forages were wilted to 45% DM, and 4 replicate bales of each legume and 8 bales of bahiagrass were wrapped in polyethylene and ensiled for 180 d. After each bale was opened, the forage was thoroughly mixed, and representative subsamples were taken for laboratory analysis and in situ incubation. Wilting and ensiling decreased the rumen-undegradable protein, water-soluble carbohydrate, crude protein (CP), and in vitro true digestibility (IVTD) of bahiagrass, perennial peanut, and cowpea, and increased their neutral detergent fiber (NDF) concentrations. Among haylages, CP concentration was greatest for annual peanut, followed by perennial peanut and cowpea, and least for bahiagrass. In contrast, NDF concentration was greater in bahiagrass than in legumes. Pigeonpea had the greatest NDF concentration among legumes and lowest IVTD of all haylages. All haylages were aerobically stable for at least 84 h, but pH was lower in perennial peanut and cowpea than in pigeonpea. Ammonia-N concentrations tended to be greater in legume haylages than in bahiagrass haylage. Butyrate concentration was greater in annual and perennial peanut than in bahiagrass. Total VFA concentration was greater in annual and perennial peanut and cowpea haylages than in bahiagrass haylage. Undegradable DM fractions were greater and extent of DM degradation was lower in bahiagrass and pigeonpea than in other haylages but lag time and degradation rates did not differ. Annual and perennial peanut and cowpea haylages were as aerobically stable and had greater CP, IVTD, and extent of degradation than did bahiagrass haylage; therefore, they are promising forages for dairy cow diets in the southeastern United States.     

Proteolysis, fermentation efficiency, and in vitro ruminal digestion of peanut stover ensiled with raw or heated corn

Peanut stover (PS) is similar to full-bloom alfalfa hay in chemical composition. The objective of this study was to assess the effect of adding raw or heated corn meal to PS at ensiling on silage N components, fermentation acids, and digestion by ruminal microorganisms. The PS was collected after harvesting of peanuts and ensiled immediately without and with addition of raw or heated corn meal (100 g/kg of fresh weight). Corn was added to PS so that the initial mixture would contain adequate dry matter (DM) (approximately 30%) and additional nonfiber carbohydrate to enhance silage fermentation. After 8 wk of silo fermentation, corn-treated silages contained less structural carbohydrates but more non-fiber carbohydrates compared with the untreated control. A shift from hemicellulose to nonfiber carbohydrate use during silage fermentation was evident by corn treatment. Additional corn at ensiling resulted in silage N with less water-soluble N, protein N, nonprotein N, nonprotein nonammonia N (peptides plus amino acids), and ammonia N. Based on changes in soluble nonprotein N before and after ensiling, the amount of proteolysis was approximately 66% for control silage and was nearly 40% lower in response to corn treatment. Adding corn increased silage lactic acid, but both acetic and propionic acids decreased. These changes were reflected in the lower pH and higher fermentation efficiency with corn-treated silages. More DM was digested and greater amounts of volatile fatty acids, except for branched-chain acids, were produced in vitro by ruminal microorganisms with corn-treated silages. In addition, incubations with silage treated with heated corn contained higher concentrations of acetic and propionic acids compared with raw corn. In vitro ammonia accumulation per unit of DM digested was lower for corn treatments than the control, and for heated corn vs. raw corn-treated silage. These results indicate that supplementation of either raw or heated corn on PS at ensiling could minimize proteolysis and improve fermentation efficiency. Advantages from using heated vs. raw corn could extend beyond silage fermentation and include rumen microbial fermentation.     

常见干豆类及豆制品中嘌呤含量研究

目的:检测常见干豆类及豆制品中的嘌呤含量,为高尿酸血症与痛风患者健康膳食提供指导。方法:采用高效液相色谱法测定嘌呤含量,色谱柱选用Waters Atlantis T3柱(4.6mm×250mm×5μm),流动相为10.0mmol/L甲酸铵(pH3.6)和甲醇(99%∶1%),流速1.0mL/min,柱温30℃,检测波长254nm。结果:不同种类干豆及豆制品中嘌呤含量具有显著差异,干豆类中嘌呤含量显著高于豆制品;干豆类中,蚕豆最高。豆制品中,豆粉最高。结论:不同种类干豆及豆制品中嘌呤含量有差别;干豆类普遍高于豆类制品。