Parboiled rice supplementation alleviates high-fat diet-induced hyperlipidemia by regulating genes and gut microbiota in mice

Dietary parboiled rice(PR)has a low risk of disease,but little is known about the contribution of PR to the prevention of hyperlipidemia.The potential role and underlying mechanisms of PR in hyperlipidemia were evaluated in this study.Male C57BL/6J mice were fed with a normal diet,high-fat diet(HFD)containing refined rice(HFDRR)or PR(HFDPR).It was found that PR intervention improved lipid accumulation in mice.Transcriptomic data analysis revealed that 27 genes were up-regulated(mostly involved in lipid breakdown)and 86 genes were down-regulated(mostly involved in inflammatory responses)in the HFDPR group compared to the HFDRR group.And 15 differentially expressed genes(DEGs)were validated by quantitative real-time PCR(RT-qPCR),while protein interaction network showed that protein tyrosine phosphatase receptor type C(PTPRC)has a central role.The gut microbiota of mice was also altered after different dietary treatments,with higher ratio of Firmicutes and Bacteroidetes,increased abundances of Ruminococcaceae,Lachnospiraceae,Christensenellaceae,Porphyromonadaceae,Rikenellaceae and Prevotellaceae,and decreased abundances of Lactobacillaceae,Peptostreptococcaceae,Erysipelotrichaceae and Actinobacteria in the HFDRR group.In addition,it was observed that PPAR signaling pathway may act as a bridge between DEGs and differential gut microbiota.These results suggested that PR can prevent hyperlipidemia by modulating liver genes and gut microbiota.

Relationship Between Degree of Starch Gelatinization and Quality Attributes of Parboiled Rice During Steaming

Paddy rice samples were parboiled by soaking at 65℃ for 180 min and steaming at 96℃ for 2–10 min,and then dried to achieve the final moisture content of 11% ± 1%. The degree of starch gelatinization （DSG） andseveral quality attributes （head rice yield （HRY）, color value and hardness） of parboiled rice were measured.Results showed that DSG （46.8%–77.9%）, color value （18.08–19.04） and hardness （118.6–219.2 N） allincreased following steaming. In contrast, the HRY increased （64.8%–67.1%） for steaming times between 2–4min but decreased （67.1%–65.0%） for steaming times between 4–10 min. Linear relations between DSG andcolor value （R2 = 0.87）, and DSG and hardness （R2 = 0.88） were observed. The suitable DSG of parboiled riceleading to the highest HRY was found to be 62.5%, obtained following 4 min of steaming.

Traditional Parboiled Rice-Based Products Revisited: Current Status and Future Research Challenges

Parboiling is an age old technique carried out to improve rice quality. Different grain parboiling techniques have been traditionally followed and scientifically developed for preparation and industrialization of rice. The state of Assam, India produces a large number of rice varieties, some of which are traditionally processed into peculiar parboiled rice products like Hurum, Komal chaul, Bhoja chaul and Sandahguri, which are of both ethnic and possible commercial importances. In spite of extensive research carried out on parboiled rice, these products and their special parboiling techniques have not been sufficiently explored. The status of research on parboiled rice as a whole with special attention to these lesser known speciality products of Assam is extensively reviewed. Future scope of research on these products is also identified.

Effect of Soaking Temperature on Physical and Functional Properties of Parboiled Rice Cultivars Grown in Temperate Region of India

The physical and functional properties of seven parboiled rice cultivars (Jehlum, K-332, Koshar, Pusa-3, SKAU-345, SKAU-382 and SR-1) were investigated at different soaking temperatures of 60℃, 70℃ and 80℃ and it was compared with the brown raw rice of the respective cultivars. Parboiling was observed to decrease L* value and increase a* and b* values. The hardness of rice was significantly increased after parboiling and varied among the cultivars with the highest in Jehlum. Parboiling resulted in the decrease of pasting parameters with the increase in soaking temperature from 60℃ to 80℃. The pasting characteristics of parboiled rice sample showed the typical behaviour having high initial viscosity, but lower peak viscosity in comparison to raw rice. The water absorption index and water solubility indices were subsequently increased with the increase in soaking temperature.

Influence of Moisture Content,Variety and Parboiling on Milling Quality of Rice Grains

The effects of moisture content （8%, 10%and 12%）, variety （Tarom and Fajr） and parboiling on milling quality of rice as a function of milling recovery （MR）, head rice yield （HRY）, degree of milling （DOM） and whiteness were investigated. The parboiled grains was prepared with three soaking temperatures of 25 oC, 50 oC and 75 oC and three steaming times of 10, 15 and 20 min. As a result of parboiling, the increasing rates of MR and HRY values were 7.8%and 14.3%for Tarom and 9.8%and 10.0%for Fajr, respectively, and the decreasing rates for DOM and whiteness were 6.6%and 10.8%for Tarom and 6.8% and 10.5% for Fajr, respectively. Moreover, decreasing moisture content to 8%maximized MR （75.8% for Tarom and 74.3% for Fajr） and HRY （65.8% for Tarom and 57.0% for Fajr） while increasing that to 12%revealed maximum values of DOM （6.1%for Tarom and 6.2%for Fajr） and whiteness （24.8%for Tarom and 28.2%for Fajr）.

Effect of Milling and Parboiling Processes on Arsenic Species Distribution in Rice Grains

This study identified the role of milling and parboiling on arsenic(As)content and its species in large numbers of rice samples.Total As contents were 108±33μg/kg in polished rice grains(PR),159±46μg/kg in unpolished rice grains(UR),145±42μg/kg in parboiled polished rice grains(PPR)and 145±44μg/kg in parboiled unpolished rice grains(PUR).The percentages of inorganic As(iAs)were 66%±8%in PR and from 72%to 77%in other grain categories.The polishing process reduced the As content in the rice grains,removing outer part of the UR with high amount of As,whereas the parboiling technique transferred the semimetal content within the grain.Total As and iAs contents were not significantly different in UR,PPR and PUR,homogenizing its distribution inside the grains.The results allowed to understand how different operations affect As fate and its chemical forms in grains.

Iron Fortification in Parboiled Rice—A Rapid and Effective Tool for Delivering Iron Nutrition to Rice Consumers

Parboiled rice production accounts for nearly half of the world’s rice production. Its markets and consumer base are firmly established in South Asia and Africa where Fe-deficient populations are mostly concentrated. Our research group has pioneered the technology of Fe-fortification in parboiled rice and demonstrated its feasibility in significantly increasing Fe concentration in the endosperm (white rice) and its bioavailability in rice based diet. Fortification with Fe-EDTA during parboiling resulted in 10 to 50 folds increase in grain Fe concentration, depending on the grain properties among different rice varieties. However, the broken rice of Fe-fortified parboiled rice contained 5 times the Fe concentration of the full grain, which is often bought and consumed by people in low income category. The bioavailability of the fortified Fe is closely correlated with increasing Fe concentration in white rice (r = 0.90, p 50% to almost 100%, despite repeated rinsing before cooking depending on rice varieties. Perls’ Prussian blue staining and prolonged polishing showed that the in vitro Fe penetrated into the interior of the endosperm. Fortification at the rate up to 250 mg Fe kg–1 paddy rice has no deleterious effects on appearance, color and sensory quality and overall acceptance by parboiled rice consumers. It increased Fe concentration up to 27 mg Fe kg–1 of in white rice, compared with 5 mg Fe kg–1 in unfortified parboiled and raw white rice. As a result, we can conclude that parboiled rice is a ready and effective tool for improving Fe nutrition of rice consumers in these regions.

浸泡与发芽对蒸谷米镉含量的影响

目的:探讨稻谷发芽与糙米发芽两种发芽方式对蒸谷米镉含量的影响,并对工艺条件进行优化,为降低蒸谷米的镉含量提供技术参考。方法:以湘早籼24号稻谷为试验材料,设置浸泡不发芽、浸泡发芽、浸泡发芽+二次浸泡3种处理方式,分析比较浸泡、发芽与二次浸泡对稻谷发芽和糙米发芽的蒸谷米镉含量的影响,并对柠檬酸浓度、浸泡时间、浸泡温度进行单因素及正交试验优化,选出最佳蒸谷米降镉工艺条件。结果:糙米发芽的蒸谷米镉含量降低效果优于稻谷发芽,糙米发芽的二次浸泡工艺优化后,得到最佳工艺组合为柠檬酸浓度0.15 mol/L,浸泡时间24 h,浸泡温度35℃。结论:发芽可以降低镉与蛋白的结合能力,二次浸泡后镉含量显著下降,与稻谷发芽处理相比,糙米发芽工艺的蒸谷米镉含量更低,经过二次浸泡条件优化,在最佳工艺组合条件下镉降低率为56.34%。

蒸谷处理对糙米和白米食用品质、糊化性质和体外消化性质的影响

本研究对糙米、白米、蒸谷米糙米、蒸谷米白米的食用品质、糊化性质和体外消化性质进行分析。结果表明:蒸谷米糙米和蒸谷米白米的白度分别低于糙米和白米。蒸谷米糙米和蒸谷米白米的食味值(包括米饭食味值、生米食味值)分别低于糙米和白米,并且蒸谷米白米的米饭食味值为70.95±3.72,显著高于蒸谷米糙米(36.13±1.53,P<0.05)。蒸谷米糙米和蒸谷米白米的焓变[分别为(1.39±0.08) J/g、(1.32±0.04) J/g]显著低于糙米和白米[分别为(5.62±0.99) J/g、(8.32±0.17) J/g]。蒸谷米糙米和蒸谷米白米在体外消化240 min时的体外消化率分别为(57.01±0.78)%和(60.23±0.35)%,而糙米和白米在体外消化240 min时的体外消化率分别为(61.90±0.64)%和(66.10±0.16)%。与糙米相比,经过蒸谷处理得到的蒸谷米糙米白度、米饭食味值、焓变均显著降低,且蒸谷米糙米的体外消化率、快速消化淀粉(rapidly digestible starch, RDS)含量和血糖生成指数(glycemic index, GI)降低,缓慢消化淀粉(slowly digestible starch, SDS)、抗性淀粉(resistant starch, RS)含量有所升高。与白米相比,经过蒸谷处理得到的蒸谷米白米白度、米饭食味值、焓变均显著降低,且蒸谷米白米的体外消化率、RDS含量和GI降低,SDS、RS含量也有所升高。本研究可为营养健康米制品的研发提供一定基础。

柠檬酸浸泡对蒸谷糙米碾米过程中蒸谷米镉含量和品质的影响

为了解蒸谷米制备工艺中柠檬酸浸泡对蒸谷糙米的碾米特性、碾白过程中镉含量及蒸谷米品质的影响,以期依托蒸谷米加工工艺为一定程度镉污染稻米的合理利用提供数据参考。选取湖南产的2个镉含量超标的籼米样品进行蒸谷米制备,采用分层碾米的方法对柠檬酸浸泡后并经蒸煮、烘干及砻谷的糙米进行碾磨,测定不同碾白时间蒸谷米的镉含量及其碾米特性和外观品质,并测定蒸谷米的矿物质含量和蒸煮特性及其米饭食用品质进行感官评价。结果显示,柠檬酸浸泡的稻谷其蒸谷糙米的皮层更容易被碾掉,同时提高了蒸谷米单位时间的碾减率,但对蒸谷米的碎米率无显著性影响;柠檬酸会使蒸谷糙米的颜色更黄,但对蒸谷米无显著性影响;稻谷经柠檬酸浸泡促进了Cd、K、Ca、Al这4种元素自胚乳而外的迁移,对Mn和Cu元素迁移的影响较小;促进Na、Mg、Fe和Zn这4种元素由稻壳和皮层向胚乳的迁移,使蒸谷米的Na、Mg等元素的含量增加;柠檬酸浸泡后制备的蒸谷米,其米饭吸水率、体积膨胀率、碘蓝值、pH值及蒸谷米饭的硬度均显著降低,蒸谷米的色泽及其米饭的滋味、口感及综合评分等显著性提高。

蒸谷米生产过程中浸泡降镉工艺优化

为探究稻谷浸泡时的最佳降镉工艺,研究了柠檬酸浓度、浸泡温度和时间对稻米浸泡过程中镉含量的影响,以期为蒸谷米加工过程中稻谷浸泡降镉工艺提供参考。在单因素试验基础上选取试验因素与水平,根据中心组合试验设计原理,采用三因素三水平的响应面法对稻谷在浸泡过程中镉降解工艺进行了优化。结果表明,柠檬酸浓度、浸泡时间和浸泡温度均会对稻谷浸泡过程中降镉率产生影响,其中柠檬酸浓度的影响极显著。建立了降镉率与三因子的二次多项式回归模型,利用模型的响应面和其等高线对降镉率影响的关键因子及其相互作用进行分析,得到最佳工艺条件为浸泡温度71℃、浸泡时间200 min和柠檬酸浓度0.11 mol/L,其最大降镉率为52.13%。

蒸谷晚籼米的制备及其无机元素和农药残留分析

对蒸谷晚籼米加工工艺中的浸泡、汽蒸、干燥三个重要环节进行了实验,并对蒸谷晚籼米中重要无机元素含量和有机磷农药残留进行了分析。实验结果表明,蒸谷晚籼米制备过程中浸泡、汽蒸和干燥的工艺条件为:在70℃水中浸泡2.5h,于100℃下汽蒸30min,先在110℃下干燥3h后,再在60℃下干燥4h。在此条件下生产的蒸谷晚籼米爆腰率为7.6%,远低于普通白米加工的爆腰率;蒸谷后晚籼米总灰分含量比未蒸谷前增加了34.5%,其中Ca、Fe、Zn等重要无机元素的含量明显增加;此外蒸谷晚籼米中未检出有机磷农药,说明蒸谷晚籼米食用安全性高。

蒸谷米超高压浸泡工艺条件优化

利用超高压浸泡生产蒸谷米,在单因素实验的基础上,利用Box-Benhnken中心组合实验和响应面分析法,确定了提升蒸谷米品质的最适工艺条件:浸泡水用量为35%,浸泡压力为150 MPa,浸泡水温度为35℃,保压时间为7 min,此条件下,整精米率为71.38%、蛋白质质量分数为9.06%、维生素B1含量为0.40 mg/100 g、维生素B2含量为0.14 mg/100 g。与普通精白米相比较,蛋白质、维生素B1、维生素B2含量均极显著性升高(P<0.01)。

中国蒸谷米产业发展分析

蒸谷米具有营养价值高、加工品质好、出饭率高、易储藏等优点。本文较为全面地分析了国际蒸谷米市场发展情况,国内发展蒸谷米产业的主要优势、潜力及制约因素,并提出了必须稳定粮食生产,缩小年际间波动幅度;依托龙头企业建立蒸谷米原粮生产基地,提高蒸谷米产业开发水平等措施建议。

蒸谷米加工的原料适应性及营养特性研究

以41个稻谷品种为试验材料,进行蒸谷米加工,以蒸谷米得米率、整米率、爆腰率、感官评价等指标为依据,探讨不同品种稻谷加工蒸谷米的原料适应性,并对其中蒸谷米感官评价分值最高的3个品种进行了工艺优化,同时考察了产品的营养特性。结果表明:不同品种间稻谷加工蒸谷米的得米率、整米率以及爆腰率有显著差异(P<0.05),得米率最高达到77.46%,而整米率最高的达到71.24%;不同品种稻谷加工的蒸谷米产品得米率均高于同品种的白米,其中有30种差异显著(P<0.05);在整米率方面,30种蒸谷米产品显著高于同品种白米(P<0.05),1种显著低于对应的白米(P<0.05)。感官评价最高的3个稻谷品种的最适浸泡、蒸煮工艺略有差异,其中TJ118在55℃下浸泡最适时间为5 h,而TJ292和TJ610的最适时间为6 h;TJ118蒸谷米的最适蒸煮时间为15 min,TJ292蒸谷米的最适蒸煮时间为20 min,而TJ610蒸谷米的最适蒸煮时间为25 min;相对于同品种白米,感官评价最高的3个稻谷品种加工的蒸谷米中铁、磷、维生素B_1、B_2含量均有不同程度的提高。

浅色蒸谷米生产工艺研究

研究了浸泡、蒸煮、干燥等工艺对以糙米为原料生产的浅色蒸谷米品质的影响。结果表明，酸性溶液浸泡的蒸谷米颜色浅；碱性溶液浸泡可得到口感较好的产品，且出米率高；采用乙醇溶液浸泡的产品色泽、饭香和风味好。低温长时浸泡的蒸谷米颜色浅、出米率高；高压蒸煮的产品口感好、出米率高；微波蒸煮的产品口感和风味好；高湿热风干燥的产品色泽好、出米率高、饭香浓；最佳综合品质的工艺参数为：用 １％的乙醇溶液于７０℃下浸泡 ３～３．５ｈ，然后用１ｋｇ／ｃｍ~２的压力蒸煮３ｍｉｎ，再用高湿热风干燥（ Ｔ＝８０～９０℃）， ＲＨ＝５０％～６０％， ｖ＝２． ４ ｍ／ｓ），缓苏冷却后，立即碾米，所得产品感官品质好，蒸饭时间短，出米率高。

蒸谷米糠和普通米糠的理化特性分析

对蒸谷米糠和普通米糠的物理特性和化学特性进行了测定。结果表明,其物理和化学特性均发生了变化。在米糠综合利用上可以分级提取米糠油和米糠蛋白,即先分级收集一、二、三机米糠作为制油原料,生成的米糠粕与抛光机米糠混合提取米糠蛋白。

不同储藏条件下蒸谷米蒸煮特性的变化研究

为了研究储藏条件对蒸谷米蒸煮特性的影响,以大米为对照,测定不同储藏温度下蒸谷米和大米不同储藏时间的蒸煮特性指标,探索蒸谷米品质特性变化与储藏时间、储藏温度的相关性和差异性。结果表明:同批次稻谷生产的蒸谷米的吸水率、体积膨胀率、米汤pH值、米汤固形物含量、米汤碘蓝值等指标均比大米低,随着储藏时间的延长,蒸谷米的吸水率和体积膨胀率呈现先上升后下降的趋势,而大米的吸水率和体积膨胀率逐渐升高;两者的米汤pH值、碘蓝值和固形物含量均逐渐降低,但蒸谷米变化幅度较小;储藏温度对蒸谷米的米汤碘蓝值和吸水率有极显著影响(P<0.01),对大米的米汤p H值、固形物含量和碘蓝值和吸水率有极显著影响(P<0.01)。储藏时间与储藏温度的交互作用对蒸谷米的米汤pH值和吸水率有极显著影响(P<0.01),对大米米汤p H值和碘蓝值有极显著影响(P<0.01);储藏时间与两种大米的蒸煮特性指标的变化均有极显著相关性,与蒸谷米的蒸煮特性指标的相关系数绝对值均大于0.736,而与大米的蒸煮特性指标相关系数绝对值均大于0.923,与大米相比,蒸谷米的各蒸煮特性指标受储藏时间影响相对较小,能更好地保持食味品质,有利于安全储藏。

储藏温度对蒸谷米糊化特性的影响

为了研究储藏温度对蒸谷米糊化特性的影响并探究其储藏特性,以同批次稻谷生产的大米为参照,模拟低温(15℃)、常温(25℃)和高温(35℃),湿度为75%的储藏环境条件,储藏期为300 d,每30 d取样1次,采用快速黏度仪法对不同储藏温度下蒸谷米和大米样品的糊化特性指标(峰值黏度、最低黏度、最终黏度、衰减值、回生值、峰值时间和糊化温度)进行测定,并对数据进行相关性分析和因素方差分析。结果表明:大米的峰值黏度、衰减值随着储藏时间的延长先升高后降低,最低黏度、最终黏度、回生值、糊化温度随着储藏时间的延长逐渐升高,峰值时间呈现波动小幅升高趋势。而同批次稻谷生产的蒸谷米峰值黏度、最低黏度、最终黏度、衰减值和回生值均比大米低,峰值时间和糊化温度比大米高,随着储藏时间的延长,蒸谷米的峰值黏度、最低黏度、最终黏度和回生值呈先升高后降低的趋势,温度越高变化幅度越大,蒸谷米的衰减值、峰值时间、糊化温度基本稳定;储藏温度除对大米的糊化温度有显著影响外,对蒸谷米和大米的其他糊化特性指标均有极显著影响(P<0.01);储藏时间与储藏温度的交互作用对大米的糊化特性指标均有极显著影响(P<0.01),但对蒸谷米的糊化温度无显著影响(P>0.05),且对峰值时间有显著影响(P<0.05)。储藏时间除与大米的峰值黏度无显著相关、与峰值时间有显著相关外,与其他糊化特性指标均极显著相关,且相关系数绝对值在0.471及以上;而储藏时间与蒸谷米的衰减值、峰值时间显著相关,与糊化温度极显著相关,相关系数绝对值在0.386及以上。储藏期内,与大米相比,蒸谷米的各糊化特性指标受储藏时间影响相对较小,表明蒸谷米能更好地保持淀粉结构和糊化特性,具有良好的储藏稳定性。

不同储藏年限稻谷的品质及蒸谷米加工适应性分析

为了解不同储藏年限的稻谷加工蒸谷米的品质变化,为蒸谷米加工原料的选择提供依据。以不同储藏年限的籼稻、粳稻各40份样品为研究对象,将其加工成蒸谷米,并对蒸谷米的蒸煮特性、外观及其制备米饭的食用品质与质构特性等指标进行测定,采用描述统计分析、方差分析、主成分分析等方法对蒸谷米的品质指标进行分析,采用聚类分析探讨稻谷的蒸谷米加工适应性。结果表明:随着原料稻谷储藏年限的延长,蒸谷米吸水率、体积膨胀率均呈上升趋势,与储藏1年的稻谷相比,储藏4年的籼稻和粳稻加工成的蒸谷米吸水率分别增加49.1%和35.9%,体积膨胀率分别增加70.6%和66.6%;米汤pH值、碘蓝值和固形物含量均无显著变化;感官评价总分均降低,米粒色泽加深,外观结构变差,米饭的适口性、滋味均降低,其中籼型蒸谷米的感官品质较粳型蒸谷米好;蒸谷米米饭质构特性各指标中除硬度、咀嚼性呈上升趋势以及粳型蒸谷米米饭的黏着性呈下降趋势外,其他各项指标无显著变化。在感官品质评价的基础上,引入质构特性指标分析,对蒸谷米的品质进行综合评价;并利用主成分分析,构建了蒸谷米品质评价的数学评价模型;再对综合评分进行聚类分析得出品质分类,并统计各储藏年份的样品数量,由此证实籼稻加工蒸谷米适应性优于粳稻,且储藏1、2年的籼稻加工蒸谷米品质较好。