Investigation of Properties of Long-grain Brown Rice Treated by Low-pressure Plasma

The impact of low-pressure plasma treatment on the properties of long-grain brown rice was investigated, and the process of quick cooking brown rice was developed. The microstructure of the brown rice surface and the cooking, textural, and pasting properties of plasma-treated brown rice were determined. Indica brown rice was treated for 30 min at voltage settings of 1, 2, and 3 kV. The plasma treatment resulted in the etching of the brown rice surface, which allowed water to be easily absorbed by the rice kernel during soaking. After plasma treatment, the cooking time, elongation ratio, width expansion ratio, water absorption, and cooking loss of brown rice were all reduced. Plasma treatment caused a significant decrease in peak viscosity and breakdown. In addition, the decreases in enthalpy and crystallinity, measured by differential scanning calorimeter and X-ray diffractometer, showed that the starch structure of brown rice was influenced by low-pressure plasma. Thus, low-pressure plasma is a novel processing technology to modify and reduce the cooking time of brown rice.     

低温等离子体技术改善糙米蒸煮品质工艺优化及热力学特性研究

为解决糙米蒸煮时间长、口感粗糙等问题,提出以低温等离子体处理糙米的新技术。以糙米为原料,探究低温等离子体工艺中辉光强度、处理时间和水分含量对糙米蒸煮时间和固形物损失率的影响规律,并通过差示扫描量热法(DSC)分析白米、糙米和低温等离子体处理后糙米的热力学性质。在单因素实验的基础上采用正交实验优化得到的低温等离子体工艺参数为:辉光强度1.8 A,处理时间2 min,水分含量9.33%,在此条件下蒸煮时间为25.31 min,固形物损失率为19.18mg/g。热力学实验分析发现低温等离子体处理可以降低糙米的热相变温度、终止温度和焓值。可为低温等离子技术在糙米生产中应用提供参考。     

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。     

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...     

几种糙米性质研究及隆粳软1号糙米蒸煮条件优化

对几种糙米的成分、断面结构以及RVA特征谱进行研究,同时优化了新型米种隆粳软1号的蒸煮条件,为更好地探究新型米种的性质及其应用前景提供了研究思路和理论基础。本研究采用RVA-Super4快速粘度分析仪进行糙米粉糊化特性的快速测定,并测定了不同米种水分、总淀粉、蛋白质、脂肪、直链淀粉、总膳食纤维以及灰分的含量。通过单因素实验确定浸泡温度、浸泡时间、蒸煮加水量对隆粳软1号糙米蒸煮品质的影响,并结合响应面分析法得到隆粳软1号糙米最佳蒸煮工艺条件为:浸泡时间40 min,浸泡温度38 ℃,蒸煮加水量为1:1.8,此条件下隆粳软1号糙米蒸煮食味品质较好,硬度与黏度比值为32.98±0.21,为解决新型米饭蒸煮问题提供了参考。     

响应面法优化糙米微波改性工艺

以糙米为研究对象,采用微波改性处理提高糙米的蒸煮品质,确定最佳复合处理条件。通过单因素实验确定微波时间、微波功率和糙米初始水分含量对糙米蒸煮品质的影响程度。并结合响应面分析法与期望函数优化微波改性处理工艺。结果表明,微波改性处理糙米的最佳工艺参数为:微波功率2400 W、微波时间75 s、初始水分含量14.5%,在该条件下期望函数值最高为0.76,对应的糙米饭硬度为2865.85 g,吸水率为56.96%,碘蓝值为0.57,验证实验结果与理论预测值无显著性差异(p>0.05),说明该模型回归性良好,实际实验拟合度高,对糙米蒸煮品质改性具有一定指导价值。     

不同加工精度下丝苗米品质的比较分析

为探究南方优质丝苗米在碾磨过程中品质及加工能耗的变化规律,以美香占2号为原料,通过碾磨制得碾减率(2%、4%、6%、8%、10%、12%)的米样,分析不同碾减率对大米的加工特性、蒸煮特性及食味品质的影响。结果表明,随着碾减率的增加,丝苗米加工过程中的碎米率和能耗均显著增加,蒸煮特性、食味品质不断改善。与糙米相比,当大米碾减率为2%时,留皮度由99.80%降低至52.83%,碎米率增加至2.74%,能耗为87.50 k J/kg,蒸煮特性与食味品质显著提升;当大米碾减率为8%时,留皮度降低至3.43%,其食味品质与精白米无显著区别;当大米碾减率达到12%时,留皮度降低至1.10%,碎米率增加至28.97%,能耗增加至1090.00 k J/kg,最适蒸煮时间缩短到18.33 min、感官评价总分提高到79.00。根据不同需求选择适宜的加工精度,更有利于节约能耗,提高粮食利用资源。     

易煮全谷物糙米加工技术研究进展

全谷物糙米蒸煮时间长、不易熟化、适口性和消化性较差,且储藏周期短,限制了糙米粒食的消费与推广.为改善全谷物糙米蒸煮特性和满足消费者对全谷物糙米健康属性的追求,利用先进的加工技术提升其食用品质、营养功能性和储藏稳定性已成为当今全谷物糙米的研究重点.阐述了全谷物糙米的成分组成及结构特点,分析了影响全谷物糙米蒸煮品质的主要因素;重点介绍了近年国内外采用的生物和物理加工技术以及新型非热加工技术在全谷物糙米加工中的应用,并阐明其工作原理及作用特点,指出了各种加工技术存在的优缺点;对未来糙米粒食的研究方向进行了展望.本研究旨在为创制高品质、高营养、高生物利用度的易煮全谷物糙米产品提供参考.     

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%。     

Influence of microwave heating as accelerated aging on physicochemical,texture, pasting properties,and microstructure in brown rice of selected Indian rice varieties

Most of the population does not prefer to consume brown rice because of its strong nutty and chewy texture imparted by bran and germ. The present study has been undertaken to investigate the influence of accelerated aging through microwave (MW) heating at a lower and higher MW power levels of 950 and 1,400 W for 72 and 91 s to observe the changes in physicochemical, texture, pasting properties, sensory attributes, and microstructure of selected rice varieties (Sona masuri and RNR-15048) stored as brown rice for 6 months. The results revealed a significant decrease in moisture, amylose, free fatty acids (FFAs) with changes in color (L*, a*, and b* values) in both the varieties treated at 1,400 W for 91 s. An increase in kernel elongation ratio, water uptake, and a decrease in cooking time and solid loss was noted in both the varieties. After cooking, the texture of both the varieties showed an increase in hardness with reduced stickiness at both lower and higher MW power levels of 950 W for 72 s and 1,400 W for 91 s compared to untreated brown rice with an improved porous structure when observed under SEM analyzer followed by better water absorption and organoleptic properties after cooking. The reduction in final viscosity has been noted in both the varieties at 1,400 W for 91 s due to the binding of FFA with starch. Thus, the MW power level of 950 W for 72 s and 1,400 W for 91 s showed the better results for short-grain varieties like Sona masuri and RNR-15048 stored as brown rice.     

对广东省三种籼稻谷的品质分析

本文对广东省内产的3种籼稻谷（中二软占、特籼占25、珍桂矮1号）质量进行品质分析（出糙率、不完善粒、整精米率、垩白粒率、垩白度、粒型、胶稠度、直链淀粉含量、食味品质）。结果表明：3种籼稻谷质量存在明显差异。     

Ohmic heating for cooking rice: Electrical conductivity measurements,textural quality determination and energy analysis

In this study, an innovative technique, namely ohmic heating was applied in rice cooking and compared with conventional method using electric rice cooker. Four types of rice samples including white rice of two varieties (KDML105 and Sao Hai), brown rice and germinated brown rice of one variety (KDML105) were used. Electrical conductivities of mixtures between rice samples and 0.1 M salt solution at various ratios were measured. Empirical models were developed for predicting electrical conductivities of rice samples as a function of temperatures. Textural properties of cooked rice samples and energy consumption were compared between ohmic and conventional cooking methods. The purposes of this work were to (1) study the possibility of applying ohmic method in rice cooking and (2) compare between cooking rice by ohmic and conventional method. The results revealed that it is possible to apply ohmic method for cooking all rice samples by using 0.1 M salt solution in the mixtures. The electrical conductivities of white rice (KDML105), white rice (Sao Hai), brown rice and germinated brown rice (KDML105) mixtures were 0.246–0.900, 0.375–1.005, 0.617–1.370 and 0.485–1.182 S/m respectively. The rice cooked by ohmic method had significantly different textural properties from that cooked by electric rice cooker. The magnitude of difference depended on the rice types. The electrical energy consumption of ohmic cooking system was approximately 73–90% of energy required for conventional rice cooker.     

高压蒸煮及微波预熟工艺改良糙米品质的研究

选择糙米为原料,通过分析其经过高压蒸煮和微波预熟处理后糊化度和感官品质的变化确定最佳预熟工艺,研究预熟化对糙米营养成分、质构特性和米粉微观结构的影响.结果表明,两种预熟工艺处理后糙米淀粉含量较未处理的糙米增加了约6.54％和8.41％、总糖含量增加了20.88％和22.96％、蛋白质含量增加了2.33％和4.91％、脂...     

不同热加工方式对黑米多酚含量和结构影响研究进展

黑米富含酚酸、黄酮、花青素等多种营养成分和生物活性物质,是一种有色稻米。黑米的热加工工艺有很多种,其中以蒸煮、挤压、干燥、微波等为主要热加工方式。挤压加工使黑米中酚酸含量损失10.27%~17.82%,高温高剪切力使酚酸发生降解脱羧、聚合;干燥加工使黑米中花青素含量下降了29.91%~65.10%,酚酸下降了1.97%~18.67%,酚类化合物发生热降解;蒸煮和微波处理分别使黑米中花青素含量损失65.4%~79.8%和69.3%~85.09%,花青素转化为原儿茶酸。本文综述了黑米中酚酸、黄酮和花青素的组成和功能,以及不同热加工处理对黑米中酚类物质含量和结构的影响研究进展,以期为黑米热加工的深入研究及其作为功能性米制食品的应用提供参考。     

小苏打对糙米蒸煮及食用品质的影响

探讨小苏打对糙米饭蒸煮特性——糙米饭的外观形貌、微观结构、色度、质构特性和米汤中支链淀粉分支链长分布的影响。研究表明：小苏打溶液蒸煮糙米可使糙米皮层发生皱缩或破裂,使糙米粒的吸水率和膨胀率分别从10.03%、212.30%显著提高至15.32%和224.50%,糙米蒸煮时间显著缩短。与BR-0.0糙米饭相比,添加小苏打蒸煮的糙米饭,其颗粒表面褶皱及裂纹结构更加明显、露白增多且黄色加深。米汤中淀粉的支链淀粉B2、B3、A链比例从7.834、2.458、24.922分别降低至6.81、1.893、24.036;其硬度从1 270.76 g降低至983.72 g;黏度的绝对值由85.79 g·s升高至113.71 g·s。糙米饭的综合感官评分增加,明显提高了糙米饭的食用品质。本研究表明蒸煮糙米时添加适宜质量浓度的小苏打可显著改善糙米饭的蒸煮食用品质。     

High-temperature air fluidization improves cooking and eating quality and storage stability of brown rice

Brown rice contains many valuable active ingredients; but due to its long cooking time, hard texture, heavy rice bran taste, and short shelf life, it is not widely accepted by consumers. Herein, we developed a novel processing technology so-called high-temperature air fluidization (HTAF) to treat brown rice. The effects of the HTAF treatment at 120 °C, 130 °C, and 140 °C for 60 s at a feed rate of 80 kg/h on the quality of brown rice were investigated. The results showed that the treatment with HTAF caused fissures to form on the surface and the interior of brown rice, and these fissures appeared to facilitate the penetration of water into the rice kernels during soaking. The optimal HTAF treatment temperature was 130 °C, the water adsorption of HTAF-treated brown rice at 130 °C (TBR-130) was increased to 25.3% after soaking for 160 min, which was higher than that of white rice and untreated brown rice (UBR; 13.7%). The optimal cooking time for TBR-130 was also 5 min shorter than that for UBR. The results further showed that TBR-130 had a larger degree of volume expansion compared to that of UBR, and cooked TBR-130 had softer texture than cooked UBR. The cohesiveness and sensory quality of TBR-130 were also higher than those of UBR, and the content of flavor compounds in TBR-130 was similar to that of white rice. HTAF caused no obvious damages to the main active components or nutritional components of TBR-130. Finally, TBR-130 had better chromaticity and higher storage stability than UBR. These results demonstrate that the HTAF treatment can improve cooking and eating quality and storage stability without causing obvious damages to nutritional quality of brown rice. This technology may play important roles in an attempt to promote the use of brown rice as staple foods.     

酶解辅助预糊化技术工艺优化及风味物质差异分析

利用响应面试验设计优化糙米的酶解辅助预糊化工艺,以蒸煮时间为指标,得到最佳酶解辅助预糊化工艺条件,用气相色谱–离子迁移谱法（GC-IMS）测定白米、糙米和酶解辅助预糊化糙米及其蒸煮前后的挥发性物质。结果表明,最优工艺条件为酶解时间为4 h、酶的添加量为0.1%、预糊化时间为10 min,酶解温度为39 ℃。在酶解辅助预糊化糙米中检测到56种挥发性物质,其中醛类19种,酮类8种,酯类6种,醇类12种及其它类11种;而蒸煮后的酶解辅助预糊化糙米中检测到44种挥发性物质,其中醛类18种,酮类8种,酯类3种,醇类11种及其它类4种,且2-辛烯醛、苯乙醛、苯乙酮、乙偶姻、γ-丁内酯、戊酸、己酸、丁酸和己二烯二硫化等挥发性物质在蒸煮之后消失。糙米酶解辅助预糊化前、后挥发性风味成分改变最大的为醛类、酮类和醇类;而酶解辅助预糊化糙米蒸煮前、后挥发性风味成分改变最大的为酯类和其它类中的酸类。     

Rice degree of milling effects on hydration,texture, sensory and energy characteristics. Part 2. Cooking using fixed,water-to-rice ratios

The purpose was to assess the effects of degree of milling on hydration and textural characteristics of rice cooked using a range of water-to-rice ratios, and to compare the energy requirements when using these fixed water-to-rice ratios to the energy required when cooking with excess-water. Surface lipid contents (SLCs) ranged from 0.15% to 0.55% for non-parboiled rice and from 0.40% to 0.95% for parboiled rice. Cooking degree was assessed by measuring cooked-rice peak force, moisture content and percentage gelatinized kernels. Milling degree had little to no effect on cooking characteristics of all milled samples. Differences in cooking characteristics between milled and brown rice were less pronounced for parboiled than non-parboiled rice. Non-parboiled milled rice required the least energy to be ‘well-cooked’, followed by parboiled milled rice, non-parboiled brown rice, and parboiled brown rice (there were no significant differences between non-parboiled and parboiled brown rice). In general, excess-water cooking required more energy than fixed water-to-rice ratio cooking.     

干法、半干法和湿法磨粉工艺制备的糙米米线品质研究

采用干法、半干法和湿法3种方式将糙米磨粉制备糙米米线,干法粉碎强度10～40 Hz,半干法调节含水量为20%～35%及湿法料液比为1∶1、1∶2、1∶3、1∶4,研究了3种磨粉方式对糙米米线蒸煮品质和质构性质的影响,并分析了糙米磨粉颗粒细度及损伤淀粉含量与糙米米线蒸煮品质的相关性。结果表明,磨粉方式及磨粉工艺条件显著影响糙米米线的蒸煮、质构和感官品质,糙米磨粉颗粒细度与糙米米线最佳蒸煮时间显著正相关,与糙米米线断条率显著负相关。糙米磨粉损伤淀粉含量与糙米米线最佳蒸煮时间、硬度显著负相关,损伤淀粉含量与糙米米线断条率显著正相关。干法粉碎强度10、半干法水分调节含量20%、30%和35%、湿法粉碎料液比1∶3～1∶4时,糙米米线的品质较好。     

Cooking qualities of parboiled rices produced at low and high temperatures

The cooking characteristics of parboiled rice are related to (i) its hydration behaviour at temperatures above and below the gelatinisation point; (ii) to kernel elongation on cooking; and (iii) to the extent of amylose solubility. These properties differ among samples, depending on the parboiling conditions. Samples were prepared by parboiling paddy at 70, 80, 90, 100, 110 and 120°C. The kernel elongation on cooking and the amount of soluble amylose in the gruel were then determined. The water uptake values for raw and parboiled rice samples were determined by hydrating them at room temperature (25-30), 60 and 98°C (boiling temperature) for optimal cooking times. The rate of hydration at temperatures below the gelatinisation point increased on parboiling and, conversely, a reverse pattern above this point. Close correlations existed between the temperature of parboiling and the properties studied. The different properties studied also correlated well. The temperature of parboiling influenced the linear elongation of the kernel after cooking. The soluble amylose content was negatively correlated with the temperature of parboiling. Though the hydration properties of different parboiled samples differed among themselves, depending on the degree of parboiling, they fell into two distinct classes, viz. the samples parboiled at a temperature close to the gelatinisation point having cooking qualities similar to raw rice, and above this point qualities differing from raw rice. The water uptake values at room temperature and at 60°C, and the ratio of water uptake at 98°C and optimum cooking time to that at 60°C were found to be useful in differentiating the parboiled rices into the two classes.