发酵糙米的加工工艺

对用酵母发酵糙米的工艺进行研究。以糙米粉为试验材料,添加水、蜂蜜、盐、大麦芽粉为底物,采用活性酵母液进行发酵试验。以淀粉酶活力作为试验指标,设计包含培养基加水量、发酵温度、时间和接种量四个因素水平,通过正交试验确定糙米发酵培养基的最佳配方和最佳发酵条件。优化的工艺条件为加水量为150%,酵母接种量为4%,发酵温度为30℃,发酵时间为为4 h。糙米酵素中的α-淀粉酶含量最高,达到485 U/g。     

糙米蛋白及其酶解产物对喂食高脂饲料叙利亚金仓鼠脂质代谢的影响

以动物性蛋白酪蛋白为对照,研究了糙米蛋白及其酶解产物对叙利亚金仓鼠脂质代谢的影响。糙米蛋白及其酶解产物降低了仓鼠肝脏中总脂肪、总胆固醇和游离胆固醇含量,同时增加了粪便中脂肪及胆固醇的排出量。糙米蛋白酶解产物还可以显著降低仓鼠的体重。     

低温等离子体电流强度对糙米食用品质的影响

针对糙米蒸煮时间长、口感粗糙等问题,应用辉光放电等离子体技术对糙米进行处理,利用质构仪、扫描电镜、傅里叶近红外图谱和X射线衍射仪等分析不同电流强度对米饭蒸煮特性、感官品质、质构特性、微观结构和晶体结构的影响。研究结果表明:低温等离子体技术在一定程度上可以改善糙米的蒸煮性能和食用品质,显著提高了糙米饭的浸泡吸水率、加热吸水率、体积膨胀率和固形物损失率(P<0.05),分别增加了3%、30%、50%和0.5%左右,而显著缩短蒸煮时间到24.8 min(P<0.05);相比于对照组糙米,低温等离子体处理后糙米饭质构特性的硬度、咀嚼性和胶黏性显著减小到1566.60 g、451和709.11(2.0 A),而感官评分、弹性、黏附性和回复性显著增大,当电流强度在1.5 A时糙米饭质构特性和感官品质最佳(P<0.05)。通过扫描电镜观察到低温等离子体处理后糙米表面出现凹陷和裂缝,进一步解释了吸水率增加的原因。利用X射线衍射仪分析发现,辉光放电等离子体处理后的糙米结晶度下降,在1.5 A时达到最小值31.19%,但结晶类型未发生改变,仍为典型的A型;傅里叶近红外仪分析发现糙米亲水基团的峰值含量增加,亲水性能增加。综合来看,当电流强度处于1.5 A时糙米的食用品质最佳。研究结果表明低温等离子体技术在改善糙米食用品质方面具有潜在的应用前景。     

Germination Conditions Affect Selected Quality of Composite Wheat-Germinated Brown Rice Flour and Bread Formulations

Abstract: Brown rice has been reported to be more nutritious after germination. Germinated brown rice flours (GBRFs) from different steeping conditions (in distilled water [DI, pH 6.8] or in a buffer solution [pH 3] for either 24 or 48 h at 35 °C) were evaluated in this study. GBRF obtained from brown rice steeped at pH 3 for 48 h contained the highest amount of free gamma aminobutyric acid (GABA; 67 mg/100 g flour). The composite flour (wheat-GBRF) at a ratio of 70 : 30 exhibited significantly lower peak viscosity (PV) (56.99 – 132.45 RVU) with higher alpha-amylase activity (SN = 696 – 1826) compared with those of wheat flour (control) (PV = 136.46 RVU and SN = 1976). Bread formulations, containing 30% GBRF, had lower loaf volume and greater hardness (P < 0.05) than the wheat bread. However, the hardness of bread containing 30% GBRF (except at pH 6.8 and 24 h) was significantly lower than that of bread containing 30% nongerminated brown rice flour (BRF). Acceptability scores for aroma, taste, and flavor of breads prepared with or without GBRFs (30% substitution) were not significantly different, with the mean score ranging from 6.1 (like slightly) to 7 (like moderately). Among the bread formulations containing GBRF, the one with GBRF prepared after 24 h steeping at pH 3 had a slightly higher (though not significant) overall liking score (6.8). This study demonstrated that it is feasible to substitute wheat flour with up to 30% GBRF in bread formulation without negatively affecting sensory acceptance. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 30% germinated brown rice flour in a wheat bread formulation without negatively affecting sensory acceptance. In the current United States market, this type of bread may be sold as frozen bread which would have a longer shelf life. Further study is thus needed.     

Effect of fermented soybean product (Cheonggukjang) intake on metabolic parameters in mice fed a high‐fat diet

As a nontargeted metabolomics approach, we investigated changes in the plasma metabolite levels in a mouse model of obesity induced by a high‐fat diet and fermented soybean product diet. We analyzed the plasma samples by using ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry (UPLC‐Q‐TOF‐MS). In the present study, the animals were divided into four groups according to the diet type; normal fat diet control group (ND), high‐fat diet control group (HD), high‐fat diet plus 30% cooked soybean power (HD + S), and high‐fat diet plus 30% 72‐h fermented Cheonggukjang powder (HD + CGJ). To examine the changes in plasma metabolite levels because of high‐fat diet feeding, total cholesterol and triglyceride levels were measured. Total cholesterol and triglyceride levels were lower in the HD + S and HD + CGJ groups than in the ND group. According to partial least‐squares discriminant analysis (PLS‐DA), major metabolites contributing to the discrimination between each group were assigned as lipid metabolites in plasma, e.g., lyso‐phosphatidylcholines and phosphatidylcholines. Therefore, diets containing soy‐based food products, which are rich sources of isoflavonoids, might be helpful for controlling the lipid metabolism under high‐fat diet conditions.     

糯米与糯玉米发酵酒品质的比较

为研究糯米和糯玉米对发酵酒品质的影响,本实验选取籼糯米、粳糯米和糯玉米三种原料,测定它们的水分、蛋白质、灰分、淀粉和脂肪含量以及三种原料发酵酒的还原糖、可溶性固形物、酒精度及总酸的含量,并通过感官评定、电子舌、电子鼻进行发酵酒感官品质分析。结果表明,籼糯米、粳糯米和糯玉米中蛋白质、淀粉、脂肪含量具有显著差异（P<0.05）,糯玉米发酵酒还原糖（12.69 g/100 g）、可溶性固形物（12.89%）、酒精度（2.0%）及总酸（13.06 g/L）的含量最低,感官评分低于籼糯米、粳糯米发酵酒,但是尚在可接受范围（感官评分≥60）,显示糯玉米作为原料酿造发酵酒具有可行性。     

低温等离子体对糙米蒸煮品质和物化特性的影响

本文以糙米为原料,探究了低温等离子体对糙米的营养成分、蒸煮品质、感官品质、质构特性、糊化特性、微观结构、结晶度和近红外图谱的影响。结果表明,相比较于对照组糙米,低温等离子体处理后糙米的加热吸水率、体积膨胀率和固形物损失率显著增加到236.10%、268.25%和19.18 mg/g (P<0.05);直链淀粉、蛋白质、膳食纤维和非必需氨基酸的含量也有一定程度的增加。低温等离子体处理改善了糙米饭的糊化特性、质构特性和感官品质,有利于糙米饭品质的提升。通过对低温等离子体处理后糙米皮层微观结构的观察分析,糙米皮层遭到破坏,表面出现凹陷和裂缝;X射线衍射和近红外数据分析得出,糙米经低温等离子体处理后亲水基团增加,结晶度降低,淀粉的晶体结构被破坏,从而有助于吸水速率提升。综上,低温等离子体可以有效地改善糙米的蒸煮和食用品质,研究结果可为低温等离子在糙米生产中提供参数指导。     

米发糕的储藏品质研究

以大米为原料,采用专用发酵剂制作米发糕,研究包装方式和温度对米发糕储藏品质的影响,为方便型米发糕的工业化生产提供技术参数。结果表明,储藏温度、包装方式对米发糕储藏品质有显著影响。储藏过程中米发糕菌落总数上升,结晶度、硬度、咀嚼度增加,弹性、黏聚性和水分含量降低,导致感官品质下降。CO2气调包装后低温度储藏有利于抑制水分损失和细菌繁殖,米发糕于-18℃储藏,菌落总数、水分变化缓慢。-18℃储藏米发糕的结晶度小于4℃储藏时的结晶度。气调包装有利于保持米发糕的质构特征。米发糕采用CO2气调包装后于-18℃储藏,使米发糕的保质期可达10天以上。     

灵芝发芽糙米果液的工艺研究

目的：以发芽糙米浆、麦芽汁和黄豆芽浆作为灵芝深层发酵培养基原料,采用灵芝发酵液与果汁进行风味调配,探索工业化生产全天然灵芝保健饮料的新途径。方法：采用D- 最优混料回归设计对组成饮料的各组分体积混合比例进行优化研究,测定饮料稳定系数。结果：灵芝发酵液体积分数为27.0%、苹果汁24.9%、白葡萄汁20.2% 和橙汁27.9% 时复合得到的灵芝发芽糙米果液可以获得最佳感官评分值。使用0.2% 黄原胶作为稳定剂时,饮料稳定系数为99.3%,饮料具有较好稳定性。结论：运用D- 最优混料回归设计进行配方优化设计,具有理论上的可靠性和实际应用的可行性。     

Choosing hamsters but not rats as a model for studying plasma cholesterol‐lowering activity of functional foods

Rats and hamsters are commonly used rodents to test the efficacy of cholesterol‐lowering functional foods. In general, a diet containing 1% cholesterol for rats whereas a diet containing 0.1% cholesterol for hamsters is used to induce the hypercholesterolemia. The present study was carried out to compare hamsters with rats as a hypercholesterolemia model. Golden Syrian hamsters and Sprague Dawley rats were randomly divided into four groups and fed one of the four diets containing 0–0.9% cholesterol. Results demonstrated that serum total cholesterol (TC) in hamsters was raised 73–81% higher than that in rats fed the same cholesterol diets. Unlike rats in which HDL‐C accounted very little for serum TC, the lipoprotein profile in hamsters was closer to that in humans. We investigated interaction of higher cholesterol diets with 3‐hydroxy‐3‐methylglutary‐CoA (HMG‐CoA) reductase, low‐density lipoprotein receptor (LDL‐R) and cholesterol‐7α‐hydroxylase (CYP7A1), sterol regulatory element binding protein‐2 (SREBP‐2), and liver X receptor (LXR‐α). Results showed hamsters and rats metabolized cholesterol differently. In view that hamsters synthesize and excrete cholesterol and bile acids in a manner similar to that in humans, it is concluded that hamsters but not rats shall be chosen as a model to study efficacy of cholesterol‐lowering functional foods.     

Effect of pre‐germination time of brown rice on serum cholesterol levels of hypercholesterolaemic rats

BACKGROUND: Brown rice is unpolished rice with immeasurable benefits for human health. Brown rice (BR) and pre‐germinated brown rice (PGBR) are known to contain various functional compounds such as γ‐oryzanol, dietary fibre and γ‐aminobutyric acid (GABA). In the present study, the experimental diets containing BR and PGBR (24, 48 h pre‐germination) were used to investigate the influence of pre‐germination time of brown rice on blood cholesterol in Sprague–Dawley male rats. RESULTS: Hypercholesterolaemia and elevation of LDL‐cholesterol were successfully ameliorated by the experimental diets containing BR and PGBR (24 and 48 h pre‐germination). As compared to the control sample, the pre‐germination time had a significant (P < 0.05) effect on blood cholesterol of Sprague–Dawley male rats. It was also found that the significantly (P < 0.05) better effect on lipid profile of hypercholesterolaemic rats was observed by prolonging the pre‐germination time. As compared to non‐germinated brown rice, the germinated brown rice showed the higher cardio‐protective effect on hypercholesterolaemic Sprague–Dawley male rats. CONCLUSION: The present study suggests that the changes of blood cholesterol can be mainly modulated by using the PGBR rather than BR. The prolonging of pre‐germination time led to an increase in the bioactive components, thereby providing a more efficient functional diet affecting the high blood cholesterol. This study suggests that PGBR can be used instead of BR and polished rice in the human diet. Copyright © 2009 Society of Chemical Industry     

不同制粉方式制得的糙米粉性质及糙米米线品质研究

比较挤压膨化米糠回添法糙米粉、未处理米糠回添法糙米粉与全粉碎法糙米粉的糊化特性、水合特性与热特性,并将三种糙米粉制作为糙米米线后对其蒸煮品质、质构特性、结晶特性以及感官品质进行研究。结果表明,挤压膨化米糠回添法糙米粉与未处理米糠回添法糙米粉的回生值分别比全粉碎法糙米粉高14.2%与27.8%;未处理米糠回添法糙米粉的水溶性指数最高,比挤压膨化米糠回添法糙米粉与全粉碎法糙米粉分别高104.0%与99.7%。糙米米线品质方面,挤压膨化米糠回添法糙米粉制得的糙米米线蒸煮损失率最低,质构特性表明其硬度最大,且具有较好的咀嚼性与回复性;另外,挤压膨化米糠回添法糙米粉制得的糙米米线感官评价总分最高,较未处理米糠回添法糙米粉与全粉碎法糙米粉制得的糙米米线分别提高13.9%与19.2%。     

Cholesterol Lowering Activity of Ropy Fermented Milk

The effect of ropy fermented milk on serum cholesterol in rats was studied. Basic diets containing slime-forming Lactococcus lactis subsp. cremoris SBT 0495, its non slime-forming variant SBT 1275, and acidified reconstituted skim milk, with 0.5% cholesterol added, were fed to F-344 rats for 7 days. Serum cholesterol level of rats fed the ropy fermented milk were the lowest among the three treatments. The serum high-density lipoprotein (HDL) cholesterol/total cholesterol ratio of rats fed ropy fermented milk was the highest. Slime materials produced by L. lactis subsp. cremoris SBT 0495 had a beneficial effect on rat cholesterol metabolism.     

Optimizing Acceptability of Chicken Nuggets Containing Fermented Cowpea and Peanut Flours

A mixture design was used to optimize the sensory acceptability (appearance, color, flavor, texture, and overall liking) of chicken nuggets containing flours processed from fermented cowpeas (FCF) and fermented partially defatted peanuts (FPDPF). Flavor and texture acceptability correlated highly with overall liking of nuggets. Products containing 20% FCF or FPDPF alone or in combination were unacceptable. Nuggets containing a mixture of 2.5% FCF and 2.5% FPDPF were as acceptable as the control, with a sweet, chickeny flavor. This suggests market potential for such poultry products.     

不同发酵时间甜酒酿面团的超微结构与面包香气特征研究

本研究将不同发酵时间(0、24、48、72 h)的广西农家酒曲制备的酒酿应用到面包中,采用α-氨基态氮表征蛋白酶活力,利用激光共聚焦观察面团的超微结构,通过气质联用测定面包中的挥发性风味物质,并结合感官鉴评,对面包进行品质评价。结果表明:甜酒酿面团(FRD)发酵前后α-氨基氮含量没有显著性差异(p>0.05),但添加有48 h甜酒酿面团的网络结构最稳定。与发酵0 h甜酒酿面包(FRB)相比,48 h甜酒酿面包中酯类、醇类物质明显增多,尤其是辛酸乙酯、壬酸乙酯以及异戊醇,赋予面包更浓郁的花香和果香。除72 h甜酒酿面包外,各组面包比容没有显著性差异(p>0.05),48 h甜酒酿面包在感官鉴评中获得更高的分数,面包更易被接受。     

小米发糕发酵剂中乳酸菌的筛选及其在小米发糕中的应用

以5种小米品种为研究对象,通过自然发酵法制备小米发糕发酵剂,测定菌落总数、感官评定发糕品质,获得品质差异较大的2种发酵剂,并对其中的乳酸菌进行分离、纯化,通过形态学、生理生化和测序进行鉴定。且研究了乳酸菌对小米发糕含水量、pH、TTA值、糖度和感官品质的影响。结果表明,乳酸菌的计数结果分别为6.48×10~7～8.57×10~9 cfu/g,1号(长农35)制备的小米发糕品质最好,6号(长谷4号)反之。2种发酵剂中鉴定出乳酸菌包括食窦魏斯氏菌(11株)、魏斯氏菌属(18株)和柠檬明串珠菌(4株),其中优势菌为魏斯氏菌属。乳酸菌LA6-40发酵制备的小米发糕含水量39.74%、pH 6.20、TTA值5.3、还原糖含量2.27 g/100 g,感官评分77.1分,色泽金黄、口感细腻、酸甜适中、咬劲适度、弹性良好,是较为适合小米发糕制备的乳酸菌菌株。     

Composite wheat–germinated brown rice flours: selected physicochemical properties and bread application

Selected physicochemical properties of composite [wheat/germinated brown rice (GBRF)/germinated glutinous brown rice (GGNBRF)] flours at 100:0:0 (control), 70:30:0, 60:30:10, 60:40:0 and 50:40:10 (%) were evaluated. Germination (steeping at pH 3 for 24 h at 35 °C) increased free gamma‐aminobutyric acid from 2.11 to 32.7 and 2.41 to 30.69 mg per 100 g flour for GBRF and GGNBRF, respectively. The 60:30:10 and 50:40:10 composite flours exhibited the lower peak viscosity (70.42 and 68.54 RVU, respectively). The setback viscosity of composite flours containing GGNBR was significantly lower than other flours. The presence of GBRF and GGNBRF significantly lowered specific volume and expansion ratio of breads. However, all sensory liking scores, except for appearance, were not significantly different among composite flour breads. Overall liking scores of all breads ranged from 6.8 to 7.2 (like moderately). This study demonstrated feasibility of incorporating GBRF and GGNBRF up to 50% by weight in bread formulations without compromising sensory liking.     

富硒红曲米对高脂饮食小鼠脂代谢和肠道菌群的改善作用

该研究旨在探究富硒红曲米对高脂饮食小鼠脂代谢和肠道菌群的影响.选用48只C57BL/6J小鼠随机分为6组(n=8):正常饮食组、高脂饮食组、富硒红曲米的低、中、高剂量组和红曲米组.灌胃8周后,测定血清中总甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)含量,对肝脏组...     

用糙米代替玉米饲喂生长獭兔的效果研究

选用35日龄断奶獭兔60只,随机分为3组.用早籼稻糙米代替日粮中的玉米0%、50%和100%进行对比饲养试验,试验期为30天.饲养试验结束后进行屠宰试验,测定肉质、皮毛品质.结果表明：以0%、50%和100%的糙米代替日粮中的玉米,獭兔的平均日增重分别为20.72g、21.66g和21.99g,组间差异不显著（P＞0.05）;屠宰率没有显著差异（P＞0.05）;肌肉pH值、水分、粗蛋白质、粗脂肪含量差异不显著（P＞0.05）;皮张面积、被毛密度、皮张厚度、被毛长度差异不显著（P＞0.05）.表明早籼稻糙米对生长獭兔具有和玉米相同的饲喂效果和营养价值,在生长獭兔日粮中以50%和100%的比例代替玉米完全可行.     

Characterisation of Lactobacillus fermentum SM-7 isolated from koumiss, a potential probiotic bacterium with cholesterol-lowering effects

BACKGROUND: Lactic acid bacteria (LAB) have been demonstrated to have cholesterol‐reducing effects in many studies. RESULTS: Lactobacillus fermentum SM‐7 screened from ten LAB strains isolated from koumiss, a fermented milk drink, reduced cholesterol by 66.8%. It also showed acid and bile tolerance as well as antimicrobial activity against pathogenic Escherchia coli and Staphylococcus aureus. Lactobacillus fermentum SM‐7 cells assimilated 61.5% and co‐precipitated and absorbed 38.5% of the cholesterol in the media. Co‐precipitation of cholesterol with cholic acid increased rapidly at pH levels below 6. In vivo experiments using L. fermentum SM‐7 on artificially induced hyperlipidaemial ICR mice significantly decreased serum total cholesterol and total triglyceride levels, low‐density lipoprotein cholesterol concentrations and atherogenic index (P < 0.01), while serum high‐density lipoprotein cholesterol concentrations did not increase significantly (P > 0.05). The body weight and liver weight/body weight ratio of SM‐7 groups were lower than those of mice on a high‐cholesterol diet that were not given lactobacilli. There was no bacterial translocation in the liver, spleen or kidney of experimental mice. CONCLUSION: The results suggested that L. fermentum SM‐7 is a potential probiotic bacterium with cholesterol‐lowering effects. Copyright © 2010 Society of Chemical Industry