共查询到19条相似文献,搜索用时 425 毫秒
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研究玉米皮渣水解液高密度发酵生产微生物油脂的工艺条件,在10 L发酵规模水平上探讨了玉米皮渣水解液取代度、通气量、搅拌速度对生产微生物油脂的影响。在糖浓度6%,玉米皮渣水解液取代度0.8,通气量0.5 m3/(m3.min),搅拌速度200 r/min,发酵温度(28±1)℃,发酵周期96 h时,菌体生物量达19.43 g/L,油脂含量为42.37%,油脂产量为8.24 g/L。通过气相色谱分析微生物油脂的化学组成,主要成分为C16及C18脂肪酸,与植物油相似,同时转酯化制备的微生物柴油达到了国家标准。 相似文献
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研究了碱性水解小桐子油脂制备脂肪酸的较佳工艺条件:油水比(g/g)为2:1,乙醇-水比(v/v)为2:1,皂化时间1.5h、温度70℃,在该条件下脂肪酸得率、酸值和碘值的平均值分别为:98.25%、203.67mgKOH/g和109.89g/100g。采用桐油、光皮油、棕榈油和大豆油等植物油脂考察了该工艺的原料适用程度,该水解工艺条件下各种油脂制备所得的脂肪酸得率和酸值都接近98%和199mgKOH/g。采用GC-MS分析五种植物油脂脂肪酸组成和含量,其不饱和脂肪酸含量依次为:桐油(94.88%)>大豆油(84.07%)>光皮油(81.90%)>小桐子油(77.84%)>棕榈油(77.19%);其中多价不饱和脂肪酸含量次序为桐油(85.36%)>大豆油(58.01%)>棕榈油(56.81%)>光皮油(55.31%)>小桐子油(42.16%)。大豆油、棕榈油、光皮油和小桐子油四种植物油脂脂肪酸成分基本相同,主要是亚油酸、7,10-十八碳二烯酸、油酸。桐油中脂肪酸组成与其他植物油脂有较大区别,含大量三价不饱和脂肪酸,其主要成分有油酸(9-十八烯酸)13.83%、8,11-十八碳二烯酸24.37%、亚麻酸(9,12,15-十八碳三烯酸和6,9,15-十八碳三烯酸)60.01%。 相似文献
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植物油脂水解工艺及不饱和脂肪酸组成研究 总被引:1,自引:0,他引:1
研究了碱性水解小桐子油脂制备脂肪酸的较佳工艺条件:油水比(g/g)为2:1,乙醇-水比(v/v)为2:1,皂化时间1.5h、温度70℃,在该条件下脂肪酸得率、酸值和碘值的平均值分别为:98.25%、203.67mgKOH/g和109.89g/100g。采用桐油、光皮油、棕榈油和大豆油等植物油脂考察了该工艺的原料适用程度,该水解工艺条件下各种油脂制备所得的脂肪酸得率和酸值都接近98%和199mgKOH/g。采用GC-MS分析五种植物油脂脂肪酸组成和含量,其不饱和脂肪酸含量依次为:桐油(94.88%)〉大豆油(84.07%)〉光皮油(81.90%)〉小桐子油(77.84%)〉棕榈油(77.19%);其中多价不饱和脂肪酸含量次序为桐油(85.36%)〉大豆油(58.01%)〉棕榈油(56.81%)〉光皮油(55.31%)〉小桐子油(42.16%)。大豆油、棕榈油、光皮油和小桐子油四种植物油脂脂肪酸成分基本相同,主要是亚油酸、7,10-十八碳二烯酸、油酸。桐油中脂肪酸组成与其他植物油脂有较大区别,含大量三价不饱和脂肪酸,其主要成分有油酸(9-十八烯酸)13.83%、8,11-十八碳二烯酸24.37%、亚麻酸(9,12,15-十八碳三烯酸和6,9,15-十八碳三烯酸)60.01%。 相似文献
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通过单因素试验,探讨了蛋白酶和淀粉酶分步水解制备玉米皮膳食纤维(DF)的最佳反应时间,再通过正交试验确立了木聚糖酶制备改性玉米皮膳食纤维(MDF)的工艺条件。结果表明,蛋白酶用量0.4%,在52℃,pH7.0的条件下反应60min;淀粉酶用量0.2%,在90℃下反应30min,DF的的产率为86.4%,其中水溶性膳食纤维(SDF)含量为1.17%,非水溶性膳食纤维(IDF)的含量为83.42%。与玉米皮相比,DF中蛋白质和淀粉含量分别降低了78.61%和91.72%。木聚糖酶制备MDF的最佳条件为木聚糖酶用量0.7%,pH6.5,55℃,反应2h,MDF的得率达到78.74%,其中水溶性膳食纤维含量为14.27%,非水溶性膳食纤维含量为63.21%,MDF的持水力、结合水力和膨胀力均比DF有所提高,分别为5.08g/g、6.31g/g和4.50mL/g。 相似文献
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为获得高品质的光皮梾木油以作为生物柴油原料,采用低温预榨-亚临界正丁烷提取光皮梾木油,测定油脂提取率及光皮梾木油理化性质和脂肪酸组成,并利用热重分析仪、流变仪、傅里叶红外光谱仪分别对光皮梾木油的热稳定性、流变特性和官能团进行表征。结果表明:采用低温预榨-亚临界正丁烷提取光皮梾木油的油脂提取率为98.54%;光皮梾木油的酸值(KOH)为1.50 mg/g,碘值(I)为100.24 g/100 g,皂化值(KOH)为189.71 mg/g,折光指数为1.472 9;光皮梾木油的脂肪酸组分主要为亚油酸(38.70%)、棕榈酸(34.80%)和油酸(22.10%),不饱和脂肪酸的相对含量为64.73%;流变学分析结果表明光皮梾木油为非牛顿流体;热分析表明光皮梾木油具有一定的热稳定性;红外光谱分析表明光皮梾木油中富含不饱和脂肪酸,是制备生物柴油的优良原料。综上,采用低温预榨-亚临界正丁烷提取光皮梾木油,油脂提取率高,所提取的光皮梾木油热稳定性好、酸值低,可为生物柴油的制备提供优质原料。 相似文献
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《食品科技》2016,(2)
玉米皮和玉米酒糟中含有5%~12%的油脂,这些油脂还含有丰富的植物甾醇和玉米黄素,由于提取技术等限制,并未能加以有效利用。研究采用太赫兹波处理联合亚临界萃取技术从玉米皮中获得了玉米皮毛油,得率为5.12%,提取率相较于索氏提取为145.04%;并分别测定了油的酸值、碘值、过氧化值、皂化值、总植物甾醇及总玉米黄色素含量。结果表明:玉米皮毛油的脂肪酸组成与文献报道的玉米酒糟(DDGS)毛油和玉米胚芽毛油相近,亚油酸含量超过50%,但其亚麻酸含量是玉米酒糟毛油和玉米胚芽毛油的2倍;且玉米皮毛油中总植物甾醇、总玉米黄素的含量分别为3.87%和2073.22μg/g,都显著高于玉米酒糟毛油和玉米胚芽毛油,是一种极具开发潜力的优质保健食用油新资源。 相似文献
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以鲜玉米皮为原料,利用酶法提取玉米皮阿拉伯木聚糖(arabinoxylan,AX),对提取物分别进行气相色谱分析和高效体积排阻色谱分析,研究Grindmyl Powerbake 950、Pentopan mono BG、Viscozyme L、Amano HC 90四种食品工业中常见的木聚糖酶提取所得提取物的单糖组成和分子质量分布,筛选出提取玉米皮AX的最佳酶制剂,并确定酶的最适添加量。结果表明:采用酶法提取玉米皮AX,其单糖组成主要是阿拉伯糖和木糖。以Amano HC 90提取24 h的玉米皮AX,其纯度为70.51%,提取率为(17.37±2.74)%,重均分子质量为(67.87±1.46)×104 g/mol,数均分子质量为(15.06±0.09)×104 g/mol,相对分子质量分散系数为4.51±0.13。经Amano HC 90提取得到提取物中AX含量较高,提取率适当,分子质量高且分散均匀,更适合食品工业中鲜玉米皮中大分子质量AX的提取,其最适添加量为1 500 U/g。 相似文献
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玉米麸皮不同处理及其成分分析 总被引:1,自引:0,他引:1
为探讨玉米麸皮的生理功能,需对玉米麸皮进行处理。通过酶处理除去玉米麸皮中含量较多的蛋白质和淀粉,得到精制玉米麸皮并确定最佳酶解工艺。再分别对精制玉米麸皮进行酸碱处理,得到相应的酸碱解产物。对玉米麸皮、精制玉米麸皮、酸解产物和碱解产物基本成分组成及膳食纤维组成进行分析。结果显示碱性蛋白酶去除玉米麸皮蛋白质的作用要好于酸性蛋白酶和中性蛋白酶。蛋白酶和淀粉酶能使玉米麸皮中的蛋白质和淀粉由10.32%和17.5%分别减少到1.65%和1.23%。精制玉米麸皮总膳食纤维比玉米麸皮增加26%。酸解产物和碱解产物基本成分是可溶性膳食纤维,其中可溶性半纤维素分别为83.52%和86.82%,不含纤维素和木质素。 相似文献
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The objective of this study was to determine the effect of substituting corn bran (CB) for dried ground corn grain (CG) in the nonforage portion of high-forage (HF) and low-forage (LF) diets. Twelve multiparous and 12 primiparous Holsteins were assigned to 4 diets using six 4 × Latin squares with 3-wk periods. Forage was 64 or 38% of the total mixed ration (% of dry matter). On a dry matter basis, the HFCG diet had 20% CG, the LFCG diet had 39% CG, the HFCB diet had 19% CB, and the LFCB diet had 38% CB. Digestible organic matter intake (OMI) and milk energy yield were lower for CB compared with CG within forage level. Digestible OMI was greater (1.9 kg/d) for the LFCG compared with the HFCG treatment. When CB replaced forage (LFCB vs. HFCB), digestible OMI was not different but milk energy yield was greater with the LFCB diet. The LFCG diet supported the greatest milk, milk protein, and milk energy yield. Decreased concentration of milk protein and increased concentration of milk urea nitrogen when feeding CB compared with CG suggests that lack of fermentable energy in the CB diets may have limited rumen microbial protein synthesis. Total substitution of CG with CB in the nonforage portion did not support maximum milk production, even when forage was reduced at the same time (HFCG vs. LFCB). Predicted neutral detergent fiber (NDF) digestibility at 1 times maintenance, based on chemical analysis of the individual feeds, was 22 percentage units greater for CB than for the forage mix (68.9 vs. 46.9%). In vitro NDF digestibility (30 h) was 19.4 percentage units greater for CB than for the forage mix (68.9 vs. 49.5%). However, in vivo NDF digestibility of the diet when CB replaced forage (HFCB vs. LFCB) was similar (44.1 vs. 44.5%). Similarly, predicted total digestible nutrients at the production level of intake, based on chemical analysis, were greater for the CB treatments and lower for the CG treatments than those observed in vivo. 相似文献
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李润国 《冷饮与速冻食品工业》2003,9(4):1-3
介绍了膳食纤维的作用,讨论了玉米皮纤维的浸泡条件为45℃、6h,确定了其在冰淇淋中的添加量为7%,并通过正交试验确定了冰淇淋的最佳配方。 相似文献
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Thirty-nine lactating Holstein cows (23 multiparous and 16 primiparous) were randomly assigned to 1 of 3 dietary treatments in a crossover design. Dietary treatments differed by the proportion of corn bran [10, 17.5, and 25% dry matter (DM); designated as low, medium, and high] replacing corn silage and alfalfa. The corn bran coproduct contained 8.2% moisture and 12.9% crude protein, 30.4% neutral detergent fiber (NDF), and 45.0% nonfiber carbohydrate, 9.9% ether extract, and 0.70% P (DM basis). The low treatment consisted of 15.8% NDF from forage (fNDF) and 33.1% total NDF; the medium treatment consisted of 12.9% fNDF and 32.5% total NDF; and the high diet contained 9.9% fNDF and 31.8% total NDF. Dry matter intake was not affected by treatment. The percent milk fat decreased by 0.26% with the inclusion of corn bran from 10 to 25% of the diet DM, but total milk fat yield was not affected. In comparison, corn bran increased yield of milk protein 0.12 kg/d when bran increased from 10 to 25% of the diet DM. Total milk yield tended to increase when bran increased from 10 to 25% of the diet DM, but no differences were observed on 3.5% fat-corrected milk. Lastly, feed conversion significantly improved with increasing inclusion: 1.39, 1.39, and 1.55 ± 0.05 kg of milk/kg of DMI for low, medium, and high, respectively. Observed effects were likely due to the increase in energy intake associated with increasing levels of corn bran. 相似文献
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以玉米麸皮为原料制备膳食纤维粉,采用木聚糖酶对其进行改性,以提高膳食纤维品质。通过木聚糖酶法,可溶性膳食纤维得率为27.49%;其最适反应条件为:木聚糖酶添加量25.7 U/g、酶解时间1.96 h、酶解温度56.09℃、酶解pH 4.68。 相似文献