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1.
丹野   《粮油食品科技》2020,28(6):47-56
白未熟粒の多発生は,整粒歩合を低下させ検査等級を下げるため,抑制する必要がある。白未熟粒,その中でも乳白粒と基部未熟粒の発生率に品種間差異があった。白未熟粒は,止葉切除による光合成の減少,増肥とそれによるm2当たり籾数の増加,疎植および育苗時の高温で生じる早期異常出穂による穂揃い不良,および刈り取り時期の遅延により増加した。倒伏により青未熟粒?白未熟粒は多くなった。初期生育が良好な場合,分げつ期からの深水灌漑は過剰分げつ発生を抑制し,粒重と玄米収量を増加させ,玄米品質も向上させた。登熟期の土壌の過乾燥により,腹白粒発生による品質低下や千粒重減少による減収を生じた。これら白未熟粒の発生は,出穂期から出穂揃い期10日後までの茎葉から籾への非構造性炭水化物(NSC)の1籾当たり転流量および粗玄米収量から同転流量を減じた1籾当たりNSC増加量が多いほど,少なかった。白未熟粒の多発生回避には,施肥量,栽植密度,育苗ハウスの温度管理,移植時期,登熟期の土壌水分および刈り取り時期を適正化し,初期生育を促進し,過剰分げつを深水で抑制する必要があった。以上の栽培法改善と,1990年代後半以降からの共同乾燥調製貯蔵施設での色彩選別機を使った1等米調製により,北海道の1等米比率は全国平均を上回るようになった。  相似文献   

2.
将水分为16.0%~18.6%的新收割优质稻谷采用包装打围、中间散存的方式储藏,分别使用热风就仓干燥,自然风就仓干燥和低温储藏干燥等方法进行干燥处理,同时也使用低温烘干机和自然晾晒等方法进行干燥处理。结果表明:各种干燥处理都达到了满意的效果,达到预期干燥水分,干燥均匀,未增加裂纹粒(爆腰粒),发芽率、黄粒米率、整精米率、脂肪酯值和粘度等重要品质指标未发生明显变化,品质新鲜。通过试验找到了稻谷保鲜干燥方法,可与保鲜储藏稻谷的方法配套,为保鲜大米加工常年提供新鲜稻谷原料。  相似文献   

3.
快餐米粉口感良好 ,营养丰富 ,易于消化吸收 ,开水冲泡即可食用 ,是外出工作、旅游的方便食品。快餐米粉的加工技术是 :1 选米 粳糙米、籼糙米、糯糙米均可。除去其中的谷粒、稗粒、碎粒、未熟粒、泥沙及金属等杂质 ,并用流水冲洗。2 干燥 将冲洗过的糙米 ,用离心机脱水 ,使含水量降至 10 %~ 15 %。也可采用垂直振动干燥 ,用微波干燥则更好。3 初碎 用粉碎机将糙米粗粉碎至粒度全通 16 0目 /5 0 μm。这种粗细度的粉体 ,在挤压膨化后 ,能获得最优的膨化效果。4 膨化 可选用单螺杆挤压膨化机 ,将糙米碎粒连续增压挤出 ,骤然降压 ,使其…  相似文献   

4.
在粮食储藏过程中,及时发现初期霉变现象,可避免损失。几种主要粮食发生霉变的早期征兆较明显的有: 稻谷:其早期变化表现为籽粒湿润变软,断面粉白,略带霉味;未熟粒、发芽粒偶见白细或绿色的霉点,发热严重的会造成黄粒。  相似文献   

5.
以未熟粒糙米为试材,研究其低氧胁迫发芽期间主要生理生化变化。结果表明:经低氧胁迫发芽48 h,未熟粒糙米的发芽率达79.3%,芽长为1.92 mm,呼吸强度提高5.6 倍,容重达0.79 g/mL;发芽期间其含水量快速增加后趋于平缓,淀粉含量持续下降,还原糖和游离氨基酸含量则逐渐增加,均与完熟粒糙米变化趋势一致且无显著性差异;未熟粒糙米中γ-氨基丁酸(γ-aminobutyric acid,GABA)含量随发芽时间延长呈逐渐增加趋势,发芽48 h时GABA含量增加1.08 倍,且谷氨酸脱羧酶(glutamate decarboxylase,GAD)活力和谷氨酸(glutamic acid,Glu)含量与对照组无显著差异。低氧胁迫下未熟粒发芽糙米中GABA含量与芽长、呼吸强度、游离氨基酸和GAD活力均呈极显著正相关(P<0.01),与淀粉和谷氨酸含量呈极显著负相关(P<0.01)。低氧胁迫发芽改善了未熟粒糙米营养品质,是富集GABA的良好原料。  相似文献   

6.
稻谷经烘干处理使水分降到13%左右,便于贮存,但这样的稻谷对加工会产生许多不利影响.通过润糙米、润稻谷等方法,调节原粮水分,可战少碎米量,提高出米率,改善成品米品质.  相似文献   

7.
稻谷爆腰产生的原因及对策   总被引:6,自引:0,他引:6  
从稻谷的是管理到收割,干燥,储藏,加工等不同的环节,分析稻谷爆腰粒产生的原因,对精米加工整米率和食叶的影响及解决的对策,以提高人们对爆腰的认识,并通过控制爆腰,满足人们对精米质量的要求,提高精米加工效益。  相似文献   

8.
粮食在储藏过程中 ,怎样准确鉴别其新陈度成了重要一环。影响稻谷鉴别的因素主要有两方面 ,一是糠粉、二是水分。1 糠粉的影响及解决办法稻谷中的过氧化氢酶主要分布于糠粉层 ,在糙米碾白过程中 ,一些糠粉依附在米粒上 ,染色时只要有新粮就会显色 ,不能准确判定新粮所占比例。如用糙米直接染色 ,就能消除糠粉的影响 ,直观看出每粒糙米着色情况 ,准确判断新粮所占比例。1 1  1%愈创木酚的配制 :量取 1ml愈创木酚 ,溶于 10ml95 %乙醇中 ,再加水至 10 0ml。因愈创木酚在水中溶解度小 ,加入乙醇液 ,增大溶解度。1 2  1%过氧化氢的配制 …  相似文献   

9.
适时收割稻谷必须充分成熟(籽粒饱满后)再收获。稻谷成熟度达到85%~90%时(85%~90%谷粒黄化)收割,边收边脱。切忌长时间堆垛和在公路上打场暴晒,以免造成粮食污染和品质下降。过早收割,会造成未充分成熟的稻谷青粒较饱满后)再收获。稻谷  相似文献   

10.
稻谷裂纹研究的现状及发展   总被引:8,自引:0,他引:8  
稻谷裂纹(爆腰)是碾米中产生碎米的重要因素。本文对国内外有关稻谷裂纹的研究作了较为详细的综述。研究表明低水分稻谷的吸湿效应是裂纹产生的主要原因。裂纹不仅可能产生于干燥后的自然冷却过程中,还可能产生于稻谷的田间生长后期以及收割、运输、干燥、储藏等各个环节中。合理地安排干燥工艺可减少裂纹的增加。  相似文献   

11.
Parboiling, a hydrothermal treatment of paddy or brown rice, impacts both head rice yield and texture and nutritional characteristics of cooked rice. Here, milling breakage susceptibility of parboiled brown rice was investigated on both bulk and kernel level. Brown rice was parboiled by soaking at 40, 55 or 65 °C and steaming at 106, 120 or 130 °C. The breakage susceptibility and changes in starch and proteins of bulk samples were related to the properties of individual rice kernels. An increase in milling breakage susceptibility from 1% to 11% corresponded to a decrease in average bending force of individual kernels from 34.9 to 14.6 N. Furthermore, both white bellies and fissured parboiled rice grains were more breakage susceptible. Their average bending force was respectively 14.1 N and 17.6 N compared to an average of 39.6 N for intact parboiled rice grains. Whereas the level of proteins extractable with sodium dodecyl sulfate containing medium had no impact, the degree of starch gelatinization was critical in determining the presence of both white bellies and fissured parboiled rice grains. More in particular, complete starch gelatinization ensured the absence of white bellies and minimized fissuring in the parboiled end-product, thereby decreasing milling breakage susceptibility.  相似文献   

12.
Milled rice surface oil and free fatty acid (FFA) contents determine rice acceptability to the brewing industry. Both could subsequently contribute to beer off‐flavors and thus compromise milled rice brewing quality. Controlling milled rice FFA by harvesting practices could be important in maintaining brewing quality as some rough rice is damaged by hull removal and/or bran disruption during harvesting. To determine the effect of harvester speed on kernel damage, the long‐grain rice variety Cocodrie was harvested at 3 different combine harvester settings and the percent of damaged kernel (w/w) was measured. Combine harvester cylinder speed had a significant effect on rough rice kernel damage. The percentages of damaged kernels for 550, 850, and 1000 rpm cylinder speeds were 1.2%, 4.0%, and 9.0%, respectively. The FFA level of milled rice with varying amount of damaged kernels was investigated over 6 mo of storage. The faster harvester cylinder speeds resulted with time in significantly greater FFA levels in “as‐harvested” rice. The FFA content of 1000 rpm as‐harvested rice almost reached the 0.1% (w/w) level. The greater the amount of damaged kernel, the greater was the milled rice FFA level, and it was significantly greater than milled rice with no damaged kernels during accelerated storage. The as‐harvested rice with 1000 rpm had the highest FFA level, followed by 850 and 500 rpm.  相似文献   

13.
Rice (Oryza sativa L.) is one of the most important cereals in the world. Before it is consumed, it is common to remove the hull, bran and germ from the rough rice kernel which is either parboiled or not. During such processing, rice kernels are subjected to mechanical stresses which cause some rice grains to break. A main challenge of the rice industry is to minimize the quantities of broken rice. We here review the factors impacting the breakage susceptibility of rice kernels. Their tendency to break is primarily determined by fissures, chalkiness, immaturity and rice kernel dimensions, properties which are both cultivar and rice grain history dependent. The intensity of processing of any given rice feedstock determines the actual level of broken rice kernels. If performed properly, parboiling, a three-step hydrothermal treatment consisting of soaking, heating and drying of rough rice, substantially reduces the level of broken kernels.  相似文献   

14.
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。  相似文献   

15.
Speciation and localization of arsenic in white and brown rice grains   总被引:2,自引:0,他引:2  
Synchrotron-based X-ray fluorescence (S-XRF) was utilized to locate arsenic (As) in polished (white) and unpolished (brown) rice grains from the United States, China, and Bangladesh. In white rice As was generally dispersed throughout the grain, the bulk of which constitutes the endosperm. In brown rice As was found to be preferentially localized at the surface, in the region corresponding to the pericarp and aleurone layer. Copper, iron, manganese, and zinc localization followed that of arsenic in brown rice, while the location for cadmium and nickel was distinctly different, showing relatively even distribution throughout the endosperm. The localization of As in the outer grain of brown rice was confirmed by laser ablation ICP-MS. Arsenic speciation of all grains using spatially resolved X-ray absorption near edge structure (micro-XANES) and bulk extraction followed by anion exchange HPLC-ICP-MS revealed the presence of mainly inorganic As and dimethylarsinic acid (DMA). However, the two techniques indicated different proportions of inorganic:organic As species. A wider survey of whole grain speciation of white (n=39) and brown (n=45) rice samples from numerous sources (field collected, supermarket survey, and pot trials) showed that brown rice had a higher proportion of inorganic arsenic present than white rice. Furthermore, the percentage of DMA present in the grain increased along with total grain arsenic.  相似文献   

16.
Paddy harvesting is the process of collecting the mature rice crop from the field which consists of activities such as cutting, handling, threshing and cleaning. Cutting, threshing and cleaning plays an important role to reduce postharvest losses. Lower performance of traditional harvesting process, labour shortage, reduced turn-around time and use of high yielding varieties have inevitably forced farmers to shift into mechanical grain harvesting in Sri Lanka. Rice milling is carried out to produce an edible polished or white rice product from harvested rough rice. Head rice yield is considered for marketing purposes because broken rice has low price in the market. Field survey was conducted in Polonnaruwa, Ampara and Hambanthota districts to identify most popular types of combine harvesters operating in the above districts. Paddy samples were collected from harvest of two most popular models of combine harvester in triplicate. Paddy sample of 1m2 area from every paddy field were harvested separately by manual harvesting followed by manual threshing and cleaning in laboratory as control sample of relevant paddy field. Moisture content of the paddy grains were measured in the paddy field using digital moisture meter before harvesting. Paddy samples were subjected to sun drying until the moisture content come down to 14±1% before the quality analysis in the laboratory. Each paddy sample was analyzed for moisture content, chaff percentage and head rice yield percentage (HRY). Paddy was milled using laboratory scale rubber roll sheller and abrasive polisher. Chaff content percentage was measured by adding 100 ml of paddy to water and volume of chaff was measured using graduated cylinder. HRY was calculated dividing the weight of grain partials, which are larger than the 3/4 of the grain, by weight of paddy sample. HRY between the two combine harvesting machine models evaluated were not significantly different at p<0.05 and also it was not significantly dependent on the harvesting methods such as combine harvesting and manual harvesting. The chaff content was significantly higher in model-2 in comparison to control sample for long grain paddy while model-1 was not significantly different with control sample for short grain paddy.  相似文献   

17.
优质籼米地下仓储藏过程中品质变化   总被引:1,自引:0,他引:1  
为探索成品粮绿色、安全的储藏方法,在南方高温高湿地区,利用地下仓储藏黄花粘和籼优998两种优质籼米,定期检测水分、碎米总量、小碎米率、垩白粒率、黄粒米、直链淀粉、品尝评分值、色泽气味、不完善率、害虫虫口密度等指标。实验结果显示,实验期间,大米水分呈小幅下降;2种大米不生虫时间长达13个月;小碎米率、色泽气味等指标无显著性变化;碎米总量、黄粒米、不完善粒含量小幅增加,直链淀粉含量逐渐增加,但均未导致大米质量等级下降;垩白粒率显著增加,品尝评分值显著下降,且均造成大米质量定等下降。根据国家标准《大米》的规定,籼优998于储藏3个月后,质量定等由二级降为三级,储藏6个月后,已不属于优质籼米,黄花粘于实验结束后仍为优质籼米三级。说明地下仓具有良好的保湿、保鲜和害虫抑制效果,优质籼米耐储性能与储藏条件和品种均相关。  相似文献   

18.
In this study, the mineral composition of germinated brown rice, brown rice, and white rice was evaluated. Brown rice grain was processed through a combination of chemical pretreatment and low oxygen treatment, after which germination was confirmed through imaging under a microscope. Using energy dispersive X-ray analysis, Mg, Al, and Cl were found to be slightly higher in germinated brown rice than in brown rice and white rice. These variations in the mineral content of germinated brown rice were attributed to the joint effect of the germination process and the prior soaking. The inability of energy dispersive X-ray to detect other minerals suggested that it was not sensitive and, hence, it was not suitable for studying elemental distribution in rice grains, or maybe the elements were not present in the rice grains studied.  相似文献   

19.
Infrared radiation (IR) is a method of drying grains that eliminates insect and microbial pests. It is unknown if IR could cause grains to be more susceptible to insects. Thus, the effects of IR on Rhyzopertha dominica development and feeding damage using long-grain rice varieties, Clearfield XL745 (hybrid) and CL152 (pureline), were examined. Rough rice was dried with three IR intensities: 2.15, 2.83, and 10.84 kW/m2. The number of progeny developed, feeding damage, and frass weight after IR-drying were compared with air-drying methods for rough rice and rice milled to brown rice after drying. Since R. dominica develop internally, X-ray technology was used to examine internal progeny and feeding damage. Progeny development and kernel damage appeared to be more affected by fraction (brown rice) than the cultivar of rice or intensity of IR used, with more progeny produced on brown rice than rough rice. An IR intensity of 10.84 kW/m2 increased the number of overall progeny, the amount of adults, and frass produced on CL152 brown rice. An intensity of 10.84 kW/m2 also increased the amount of larvae observed for both varieties and fractions. The intensity of 10.84 kW/m2, under the conditions of this study, is not recommended for drying rice.  相似文献   

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