不同制备工艺的籼米粉对面条品质的影响

采用了干法、半干法、湿法对籼米进行加工,研究了不同工艺籼米粉的理化特性差异及其对面制品所产生的影响。结果表明:3种工艺生产的米粉中,湿磨米粉白度最高,平均粒径最小,淀粉颗粒形态较其它工艺完整,半干法米粉峰值黏度、回升值、崩解值均较高;加入籼米粉的面片亮度下降,弹性升高;面条的最佳煮制时间变短,干物质吸水率升高,蒸煮损失率降低;试验还发现干法籼米粉可同时提高面条的硬度、弹性和咀嚼性。     

米粉种类及添加量对蛋糕品质的影响

以籼米、粳米、糯米为原料,用一定比例的米粉替代面粉制作蛋糕。采用感官、质构、比容等指标评价米粉种类及添加量对蛋糕品质的影响,建立米粉物性指标与蛋糕品质指标间的相关性。结果表明,米粉的种类及添加量对蛋糕的感官、质构、比容等均有显著性影响;米粉物性指标与蛋糕品质指标间均有一定相关性,其中蛋糕的口感、弹性分别与米粉添加量呈极显著负相关（-0.910）与极显著相关（0.811）;蛋糕比容分别与米粉水分含量、脂肪含量均呈极显著正相关（0.823、0.764）;回归分析得蛋糕感官总分的回归方程为:Y感官总分=1.63+0.990X蛋糕口感+1.646X米粉添加量-8.058X米粉水分含量+0.136X蛋糕外观-0.23X蛋糕比容。      

米粉种类及添加量对蛋糕品质的影响

以籼米、粳米、糯米为原料,用一定比例的米粉替代面粉制作蛋糕.采用感官、质构、比容等指标评价米粉种类及添加量对蛋糕品质的影响,建立米粉物性指标与蛋糕品质指标间的相关性.结果表明,米粉的种类及添加量对蛋糕的感官、质构、比容等均有显著性影响;米粉物性指标与蛋糕品质指标间均有一定相关性,其中蛋糕的口感、弹性分别与米粉添加量呈极显著负相关(-0.910)与极显著相关(0.811);蛋糕比容分别与米粉水分含量、脂肪含量均呈极显著正相关(0.823、0.764);回归分析得蛋糕感官总分的回归方程为:Y感官总分=1.63+0.990X蛋糕口感+1.646X米粉添加量-8.058X米粉水分含量+0.136X蛋糕外观-0.23X蛋糕比容.     

Effect of red Jasmine rice replacement on rice flour properties and noodle qualities

Food Science and Biotechnology - This study aimed to assess flour and noodle qualities after substituting Phitsanulok rice flour (PH) with red Jasmine rice flour (RJ). Blended rice flours were...     

Effect of milling on colour and nutritional properties of rice

Brown rice (long-grain variety Puntal) was abrasively milled (0–100 s) to various degrees of milling (DOM, 0–25%). The non-linear relationship between milling time and DOM indicated a variability in hardness within the different rice fractions. The hardness of the bran layers increased from outer to inner bran layers, while the different endosperm fractions were of comparable hardness. The colour parameters L^*, a^* and b^* and extinction measurements of water-saturated butanol extracts of flour, from rice with different DOM, indicated that bran contained much more yellow and red pigment than endosperm. The levels of yellow and red pigment decreased from the surface of the brown rice to the middle endosperm (DOM = 15%). Once bran (DOM = 9%) and outer endosperm (additional DOM = 6%) were removed, the yellowness and redness of the middle endosperm of the raw rice remained constant, indicating that the pigments were uniformly distributed in the middle endosperm. Cooking of rice containing residual bran layers (DOM < 9%) increased rice brightness (L^*) and decreased its redness (a^*) and yellowness (b^*), as expected from a dilution effect resulting from the uptake of water, as well as from leaching of pigments in the cooking water and diffusion of bran pigments to the endosperm. Cooking of rices with DOM > 9% resulted in products of constant brightness and redness but with yellowness which decreased as a function of DOM. Proteins, minerals and starch were not uniformly distributed in the brown rice kernel. The endosperm (DOM > 9%), contained most of the rice kernel proteins (84.2%), and proteins were mostly concentrated in the outer endosperm (9% < DOM < 15%). Bran (0% < DOM < 9%) contained most of the minerals (61.0%), and starch (84.6%) was concentrated in the core endosperm fraction (DOM 25%).     

高密度二氧化碳处理对鲜切苦瓜品质的影响

研究比较高密度二氧化碳处理、次氯酸钠处理和漂烫处理对鲜切苦瓜品质的影响。随着高密度二氧化碳处理压力提高,鲜切苦瓜中菌落总数显著降低,在6 MPa处理后,其菌落总数降低5.8 Log(CFU/g),显著高于次氯酸钠处理;同时,高密度二氧化碳处理(6 MPa)对鲜切苦瓜的细胞结构影响最小,并降低其苦味。但是,高密度二氧化碳处理后,鲜切苦瓜中抗坏血酸损失率为85%,叶绿素含量损失率为70%。因此,高密度二氧化碳处理(6 MPa)可有效减少鲜切苦瓜中微生物数量,降低其苦味。      

加工精度对米粉老化进程的影响

以质构、RVA、X-衍射和红外光谱为检测手段,分析不同加工精度（0%、3%、6%、9%）大米米粉糊化后的老化进程。结果表明,不同加工精度的米粉凝胶在4℃贮藏过程中,硬度、糊化温度、回复值、结晶度、红外（1047cm-1/1022cm-1）处吸光度比值均逐渐上升,粘度逐渐下降;贮藏前3d,各指标均变化较快,第7d后趋于平缓,表明前3d米粉糊迅速老化,第7d后老化基本完成。相同老化时间下,糙米米粉凝胶的加工精度与硬度、糊化温度、回复值、结晶度和红外吸光度比值成正比,与粘度成反比,即加工精度越高,老化越快。      

稻米加工精度对胶稠度测定的影响

通过选用不同直链淀粉含量的稻谷样品,加工成不同等级大米,测定其对胶稠度的影响,结果表明:不同加工精度的大米对胶稠度的影响程度与样品本身直链淀粉含量有关,直链淀粉含量越高,影响越大。对于直链淀粉含量大于19%的样品,加工精度相差四个等级,胶稠度测定结果可差50%～100%。     

加工精度对米粉老化进程的影响

以质构、RVA、X-衍射和红外光谱为检测手段,分析不同加工精度(0％、3％、6％、9％)大米米粉糊化后的老化进程.结果表明,不同加工精度的米粉凝胶在4 ℃贮藏过程中,硬度、糊化温度、回复值、结晶度、红外(1047cm-1/1022cm-1)处吸光度比值均逐渐上升,粘度逐渐下降;贮藏前3d,各指标均变化较快,第7d后趋于平缓,表明前3d米粉糊迅速老化,第7d后老化基本完成.相同老化时间下,糙米米粉凝胶的加工精度与硬度、糊化温度、回复值、结晶度和红外吸光度比值成正比,与粘度成反比,即加工精度越高,老化越快.     

超临界CO2流体萃取米糠油研究

通过超临界CO2流体萃取米糠油研究,总结萃取压力、萃取温度、萃取时间和物料水分含量对米糠出油率影响。结果表明,最适宜萃取条件为:萃取压力30 MPa、萃取温度45℃、萃取时间80 min、物料水分含量为5％～6％,出油率达14．32％;同时测定超临界CO2流体萃取米糠油中脂肪酸甘油酯组成,得出油酸甘油酯、亚油酸甘油酯和棕榈酸甘油酯占总脂肪酸甘油酯90％以上,其中,油酸甘油酯和亚油酸甘油酯占总脂肪酸甘油酯70％以上;通过超临界CO2法与压榨法比较,超临界CO2流体法萃取米糠油不饱和脂肪酸含量较高,理化指标也优于压榨法,因萃取温度低,防止提取过程中油脂氧化,因此超临界CO2流体萃取是一种较好提取米糠油方法。     

加工精度对大米食用品质及风味的影响

结合留皮度和碾减率表征大米加工精度,研究加工精度对大米食用品质的影响,并采用同时蒸馏提取-气相色谱-质谱联用法分析米饭中的挥发性风味物质,为大米适度加工提供借鉴.结果表明:随碾磨时间增加,碾减率变化可用一条二次曲线(R2 =0.997 3)和一条线性方程(R2=0.992 5)拟合,留皮度可由一条函数方程(R2 =0....     

碾米工序有关问题的探讨

对碾米工序中的有关问题进行了探讨,分析了碾米机理,提出了碾米工序中碾米机选配、工艺组合、操作维护等方面的建议。     

超高压处理对山楂黄酒品质的影响

文中研究了山楂黄酒经100MPa～600MPa处理15min后其理化性质、香气成分及感官品质的变化.研究结果表明,山楂黄酒经200MPa处理后,总酸显著增加(p＜0.05),而经300MPa～600MPa处理后则显著降低(p＜0.05);高压处理后其稳定性、可溶性固形物并无显著变化(p＞0.05),总糖、氨基酸态氮、pH值显著增加(p＜0.05),酒精度、电导率显著降低(p＜0.05).GC-MS结果表明:经200MPa、400MPa和600MPa处理15min后,1-丁醇、2,3-丁二醇、苯乙醇等醇类和乙酸乙酯、乳酸乙酯、丁二酸二乙酯、苯乙酸乙酯等酯类含量明显增加,乙醛含量明显降低,400MPa处理的酒样香气变化最显著.感官评定结果表明,高压处理后的山楂黄酒澄清透明,果香味突出,酒体醇厚,口感协调、饱满.     

Effect of carbon dioxide on autoxidation and photooxidation of nitrosylmyoglobin

Autoxidation and photooxidation of nitrosylmyoglobin, MbFe(II)NO, the pigment of nitrite-cured meat, was investigated in aqueous solution saturated with gas mixtures containing varying levels of CO(2) (0%, 20% and 90%) in the presence of either 1.5 or 10% O(2) and balanced with N(2) in order to mimic modified atmosphere (MA) packaging of meat products. Quantum yields for photooxidation at 1.5% O(2) for monochromatic UV-light (366 nm) were slightly higher than for visible light (436 nm) in agreement with previous findings, while the quantum yields showed no dependence on the CO(2) levels. Autoxidation of MbFe(II)NO was evaluated by global analysis of spectral data applying a kinetic model with two consecutive reaction steps, and the second rate constant was significantly reduced at the highest CO(2) level investigated, while the rate constant of the initial reaction step was found independent of the CO(2) levels. The varying dependence observed for autoxidation and photooxidation of MbFe(II)NO in relation to CO(2) level confirms the differing reaction mechanisms for the two types of MbFe(II)NO degradation. Photooxidation of nitrite-cured meat products packed in MA is accordingly expected to be independent of the presence of varying CO(2) levels, while thermal oxidation (autoxidation) of MbFe(II)NO is reduced at elevated levels of CO(2), which may be of some relevance during product storage and retail display.     

Effect of pre-harvest flooding of paddy on the milling and cooking quality of rice

The physico-chemical, milling, pasting and cooking characteristics of six cultivars of paddy, viz PR-106, PR-109, PR-103, Java, PR-108 and Basmati-370, as affected by flooding were investigated. A significant reduction in 1000-kernel weight and bulk density of paddy rice in damaged samples was observed. The kernels in flood-affected samples became soft and developed fissures which contributed to low head rice recoveries. The milled rice from them had lower kernel weight and protein content but showed higher amylose and ash content. The diastatic activity of these samples was higher. Amylographic characteristics showed no effect on the gelatinisation time and temperature in most of the samples. Peak viscosity and setback were affected in all samples, and the effect was variable among different varieties. The flood-affected samples showed lower cooking time and higher gruel solids loss, and were rated poorer organoleptically.     

Enrichment of tocols from rice germ oil using supercritical carbon dioxide

An efficient process was developed for enrichment of tocols from rice germ oil (RGO) using supercritical carbon dioxide (SC‐CO₂). Tocols were efficiently enriched in residue by removal of fatty acid methyl ester from the esterified RGO using SC‐CO₂. The enrichment of tocols was carried out at an operating pressure of 12.4–15.8 MPa, an operating temperature of 40–60 °C and a carbon dioxide flow rate of 5.0 L min^?1. The combination of 13.8 MPa pressure and 60 °C temperature was selected as the most suitable for efficient enrichment of tocols. The level of tocols (1270 mg/100 g) in the residue obtained at these operating conditions was six times higher than the tocols level (192 mg/100 g) of the starting material, namely esterified RGO. There were no significant differences in relative percentages of tocols homologues between esterified RGO and the residue obtained by SC‐CO₂ extraction.     

基于GC-IMS分析碾减率对籼米米饭挥发性物质的影响

目的：研究碾减率对籼米米饭挥发性物质组成的影响。方法：以籼稻“隆科早1号”为原料制备理想碾减率为0%~14%的籼米,同时采用气相色谱—离子迁移色谱（GC-IMS）测定米饭的挥发性物质,并根据指纹图谱结合多元统计分析籼米米饭中挥发性物质差异。结果：当碾减率为8%时,籼米米饭的感官评分最高。米饭中挥发性物质主要是醛类、酮类、醇类及少量的呋喃类等。大部分挥发性物质在碾减率为0%~6%的籼米米饭中含量较高;当碾减率为10%~14%时,米饭中的挥发性物质组成无明显差异。采用正交偏最小二乘法判别分析（OPLS-DA）筛选出 18 种特征标志物（VIP>1）,其中,2-甲基-1-丁醇、乙酸异戊酯、异戊醇、2-戊烯醛、3-甲基丁酸、2-乙基呋喃等可以作为“隆科早1号”不同碾减率大米米饭的差异性挥发性物质。结论：碾磨可以降低糙米米饭中挥发性物质含量,当碾减率为8%时,米饭具有良好的气味和感官品质。     

Effect of milling on mineral and trace element composition of raw and parboiled rice.

The effect of milling on the mineral and trace element composition of raw and parboiled grain samples of 16 varieties of rice was investigated. Varietal, locational and seasonal differences in the nutrient composition of brown rice were noted. The mean values for different nutrients per 100 g brown rice were total ash 1.37 g, phosphorus 349 mg, magnesium 157 mg, calcium 18 mg and iron 2.16 mg and in μg per g samples, zinc 14.3, manganese 11.0, copper 2.39, molybdenum 0.775 and chromium 0.088. Parboiling per se had no effect on the composition of brown rice. The degree of milling and the initial concentration of the nutrient in the grain determined the magnitude of loss on milling both in raw and parboiled grain. Percent losses of different nutrients on 5 and 10% milling of raw rice respectively were total ash 40, 62; iron 51, 67; magnesium 40, 64; calcium 36, 57; iron 54, 64; copper 26, 45; manganese 48, 56; molybdenum 24, 34; chromium 57, 69; and zinc only 2.8, 4.6. Zinc in rice grain was uniformly distributed and a major portion of other nutrients was concentrated in the outermost 2.5% surface layers of the grain. Parboiling appeared to have altered the distribution of some nutrients in rice grain except for zinc, magnesium and copper. Milling losses for other nutrients were therefore significantly lower in parboiled than in raw rice.