优质稻谷保鲜干燥方法研究

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。     

优质稻谷准低温储藏与常温储藏品质变化的比较研究

本文研究了优质稻谷在准低温储藏条件下的品质变化,并与常温储藏的品质变化做对比,以期为优质稻谷准低温储藏下的储备周期提供依据。将两种优质稻谷黄华占和两优放入实验模拟仓中储藏,控制环境温度20℃以下,以常温储藏作为对照。每两个月取样对其色泽、气味、脂肪酸值、品尝评分值、黄粒米含量、直链淀粉含量、出糙率、整精米率、过氧化氢酶活动度、发芽率等储藏品质指标、质量指标、加工品质指标、生理品质指标以及糊化特性和质构特性进行测定和分析。结果表明,低温储藏较常温储藏更能延缓优质稻谷品质的劣变,根据GB/T 20569《稻谷储存品质判定规则》,建议准低温储藏的优质稻谷的储备周期不超过18个月。     

优质籼稻控温条件下储藏品质变化规律研究

为了探究在不同温度条件下优质稻谷的储藏品质变化规律和储藏周期,以黄华占、湘晚籼13号和盛泰优18号3种优质籼稻为研究对象,在室内定期监测其储藏品质.试验结果表明:温度是优质籼稻储藏的关键指标之一,温度越低,优质籼稻色泽气味、脂肪酸值和品尝评分值等储藏指标所反映的粮食劣变程度越低.在15和20℃控温条件下,3种供试优质籼稻储藏指标在2年试验期间一直维持宜存等级,25℃控温和自然条件下,供试优质籼稻谷在试验期内不能一直维持宜存等级.因此,为延长优质籼稻储藏期,可适当降低储藏温度.     

不同氮气气调工艺启封后籼稻品质变化规律

本文为了解籼稻氮气气调启封后储藏过程中品质变化规律,以实仓储藏籼稻为原料,以常规储藏作为对照,对气调储藏和气调杀虫两种工艺启封后籼稻的品质进行检测和比对分析。结果表明：在准低温实仓储藏条件中,两种气调工艺启封后籼稻的含水量,脂肪酸值、新鲜度、发芽率、真菌孢子数和糊化特性等指标变化和常规储藏差异不明显。气调杀虫工艺在启封储藏前后籼稻的出糙率和整精米率分别比对照仓多降低0.9%和0.2%,垩白率多增加0.73%;气调储藏工艺启封储藏前后籼稻的出糙率,整精米率分别比对照仓多降低0.4%和0.34%,碎米率、垩白率、黄粒米率和硬度多增加 1.93%,2.34%,0.7%和3.5%。通过主成分分分析发现气调时间越长启封后稻谷品质变化更快、更明显。     

不同温度对稻谷储藏品质的影响

以秋收稻谷为原料,在南方高温高湿气候条件下,采用保鲜冷库10、14、18、22℃和常温储藏(CK)5组试验,通过稻谷水分、脂肪酸含量、过氧化氢酶活性度3个指标判断稻谷储藏品质,得到稻谷低温保鲜储藏最优工艺区间14～18℃。     

谷外糙米含量对稻谷储藏品质的影响

为了探讨稻谷中谷外糙米的含量对稻谷储藏品质的影响,确定稻谷中谷外糙米含量的临界值,对粳稻和籼稻样品分别加入2%、4%、6%、8%、10%的谷外糙米,以不添加谷外糙米的净稻谷和糙米作对照,在38℃,RH=75%的条件下储藏3个月,测定储藏品质,并用SPSS软件分析测定数据。结果表明,随着储藏时间的延长,脂肪酸值和丙二醛含量逐渐增高,还原糖含量上升后下降,与未添加谷外糙米的稻谷相比,添加不同含量谷外糙米的稻谷储藏品质均有不同程度的下降,谷外糙米含量越高,储藏品质指标越差。采用差异性分析法分析储藏90 d后谷外糙米含量对粳稻、籼稻品质的影响,不同含量的谷外糙米对稻谷储藏品质指标存在显著的影响。当粳稻谷外糙米含量超过8%,籼稻谷外糙米含量超过6%时,与净稻谷(0%)相比,脂肪酸值、还原糖含量和丙二醛含量均存在显著差异。粳稻谷外糙米含量不宜超过8%,籼稻谷外糙米含量不宜超过6%。     

优质稻谷常温储藏条件下品质变化研究

为了探究在常温条件下优质稻谷的储藏周期,以两种优质稻谷黄华占和两优为原料,将其储藏在模拟仓中,定期监测其储藏品质、质量指标、加工品质、生理品质、糊化特性和质构特性,通过这些品质指标的变化来界定常温储藏条件下优质稻谷的储藏周期。实验结果表明,常温储藏过程中,两种优质稻谷的储藏品质、质量指标、加工品质、生理品质、糊化特性和质构特性均下降,表明优质稻谷品质下降。储藏420 d(14个月)后,优质稻谷品质基本接近不宜存状态,因此,常温储藏条件下优质稻谷的储藏周期不应超过14个月。并且,黄华占的品质劣变较两优优质稻更为明显,粮库应该选择储藏品质更加稳定的优质稻谷进行储藏。     

低温储藏解除后长粒型籼稻的品质变化和动力学分析

目的 探讨长粒型优质籼稻低温储藏解除后的品质变化,为稻谷的品质变化及科学储藏提供理论依据。方法 本研究以广西桂林新收获的长粒型优质籼稻为对象,对低温储藏解除后的稻谷进行低温(15℃)、常温(25℃)和高温(35℃)储存180 d,每20 d取样进行品质指标检测,并进行动力学分析。结果 在3个温度条件下,稻谷的出糙率、整精米率、水分含量、发芽率、过氧化物酶活性、多酚氧化酶活性和品尝评分值呈下降趋势,黄粒米率、直链淀粉含量、丙二醛含量、脂肪酸值呈上升趋势,15℃条件下继续储存可以有效地延缓稻谷品质的劣变,低温解除前后的温差对稻谷储存前期品质变化影响较大。相关性分析表明,储藏时间和温度与稻谷各品质指标均呈显著相关性;温差与稻谷各品质指标的相关性不强。动力学分析结果表明不同温度下水分含量、丙二醛含量和脂肪酸值的变化均符合零级动力学模型,在相同储藏温度条件下,丙二醛含量的活化能均小于水分含量和脂肪酸值的活化能。结论 稻谷低温解除后,短时间储存稻谷应避免温差较大,长时间储存应在较低温度下储存,既能延缓稻谷品质劣变,又能节约储存成本。丙二醛含量可作为低温解除后稻谷品质变化的早期预测参考指标。     

稻谷霉变程度与敏感品质变化关系研究

将水分为23%、21%、19%和17%的稻谷置于模拟仓中储藏,检测其在储藏过程中霉菌菌落总数、色泽、脂肪酸值、黄粒米、丙二醛和发芽率等品质指标的变化,以期找出稻谷霉变敏感品质指标及其与稻谷霉变程度之间的关系。     

整仓环流结合压盖储粮技术对东北地区偏高水分稻谷品质的影响

采用常规储藏,整仓环流结合压盖储粮技术对东北地区偏高水分稻谷度夏储藏期间(180 d)的粮温、水分、储藏品质、种用品质和糊化品质进行对比分析。在检测期间,整仓环流结合压盖技术比常规储藏表层粮温低25.8%。整仓环流结合压盖储藏下储粮水分为14.77%,比常规储藏高0.41%。整仓环流结合压盖方式下脂肪酸值为18.66 mgKOH/100g,比常规储藏低4.86 mgKOH/100g。整仓环流结合压盖方式下发芽率为94%。糊化品质分析结果表明整仓环流结合压盖方式储藏的稻谷具有良好的加工稳定性。在东北地区采用整仓环流结合压盖储粮技术储藏偏高水分稻谷能够有效控制粮温,提高粮食的保水率,滞后脂肪酸的上升速率,保证稻谷品质。     

大米贮藏品质变化规律研究

在实验室人工模拟条件下控制大米的贮藏温度和水分,对贮藏大米进行了为期10个月的试验研究,定期检测影响大米质量的脂肪酸值等数据。结果表明：脂肪酸的变化速率与大米初始含水量、温度、贮藏时间呈正相关。研究大米贮藏品质变化规律,减少大米损失,消除劣变大米对消费者造成的安全隐患,对粮油加工和仓贮企业提供技术指导,具有重要的现实意义。     

A comparison of the functional characteristics of wheat stored as grain with wheat stored in spike form

In this study, wheat grain and wheat spike with 12%, 14% and 16% moisture content were stored at 10, 20 and 30 °C for 0, 3, 6 and 9 months. After storage, wheat samples were investigated for hectolitre weight, gluten content, Zeleny sedimentation volume, enzyme activity, acidity, phytic acid and L colour value. Storage of wheat at different storage forms (spike and grain) and storage conditions showed considerable changes in grain quality. In general, the storage period of 3 months positively affected wheat quality. However, hectolitre weight, gluten, Zeleny sedimentation, enzyme activity, acidity and colour of wheat got worse at storage periods beyond 3 months. Hectolitre weight, wet and dry gluten, Zeleny sedimentation, phytic acid content and L Colour value of wheat stored in both spike and grain form significantly decreased during storage. However, the increase in grain moisture content, storage time and temperature resulted in significant increase in total titratable acidity and falling number values of wheat. Falling Number and phytic acid values of wheat stored in spike form were generally lower than wheat stored in grain form. Storage in spike form had a positive effect on especially wet gluten content of wheat stored at non-optimal storage conditions such as high grain moisture content and high temperature. Wet gluten of wheat stored in spike form was higher than that of wheat stored grain form after storage at 30 °C for 6 and 9 months. Wheat stored in spike form is more resistant than wheat stored in grain form against adverse storage conditions such as high moisture content and temperature and longer storage time.     

动态温湿度储藏条件下糙米主要储藏特性研究

为了研究分析早籼稻在收获后,以糙米形式过夏及其储藏过程中的品质变化,将初始水分含量分别为15%、17%、19%和21%的糙米,分别在低温15 ℃左右(L组)、中温25 ℃左右(M组)、高温35 ℃左右(H组)3种不同温湿度动态条件下模拟储藏240 d,观测糙米表面颜色、脂肪酸值、质构特性、糊化特性的变化。结果表明,在温湿度动态变化过程中,储藏温度和糙米水分对糙米储藏特性和储藏后品质影响显著(p<0.05);初始水分含量则与糙米主要质构特性、糊化特性指标极显著相关,但高水分糙米储藏后主要质构特性、糊化特性指标均未见改善,脂肪酸值呈先上升后下降的趋势,糙米品质发生劣变。正常(15%)或偏高水分(17%、19%)的糙米在正常(低温和中温)储藏条件下安全储藏期为120 d,如若控温(低温)条件下可以延长正常水分糙米储藏期至180 d。糙米在入夏高温储藏时初始水分须控制在15%的安全水分以内,偏高水分(17%、19%)的糙米在高温条件下极易发生品质劣变。     

Effect of drying air temperature and storage on industrial and chemical quality of rice grains

The drying air temperature and storage time can change the milling yield and chemical composition of rice grains. Therefore, the objective was to verify the industrial quality and chemical composition of rice grains, white and integral subgroups, in response to drying air temperature and storage time. For such, the rice grains were subjected to drying in a column dryer with a grain capacity of 1 m³, using 55 and 65 °C drying air temperatures. After, they were stored in PP Woven Bags under environmental conditions for 240 days. After drying and every 60 days the milling was performed, aiming to evaluate the industrial quality and chemical composition of the grains. The whole grains yield was negatively affected by the increase in drying air temperature for both subgroups. The increase in the drying air temperature led to a reduction in the lipid content and an increase in the ash content for grains of white subgroup. The storage time promoted an increase in the whole grains yield in the white subgroup when the grains were dried with the highest drying air temperature. The lipids and proteins contents decreased, while the fibers and ash contents increased during storage for the white subgroup grains. The chemical composition of grains from the brown subgroup did not change during storage, regardless of drying air temperature.     

Technological and sustainable strategies for reducing losses and maintaining the quality of soybean grains in real production scale storage units

Soybean is the oilseed most cultivated worldwide and is in full production expansion in Brazil. However, the logistics and grain quality in post-harvest stages is increasingly concerning. The objective of this work was to evaluate different sustainable strategies of managing the mass of soybean grains in function of water content, optimizing the combined drying and storage operations to improve grain flow and quality in real production scale storage units. The experimental were consisted in two step, first: moisture soybean (SUL) (17%), dry soybean from the RR crop (SSLRR) (14%), dry soybean from the RR2 crop (SSLRR2) (14%), soybean dried in a continuous dryer (SSS1) (12%), in silo-dryer (SSS2) (14%), and in intermittent dryer (SSS3) (14%), moisture soybean (SUL) submitted to aeration drying (Silo 1), to partial drying (SSS1, SSS2, SSS3), and supplemented with aeration drying (Silo 2), dry soybean from the RR2 crop (SSLRR2) and stored in aeration (Silo 3), dry soybean from the RR crop (SSLRR) and stored in aeration (Silo 4), and second step: the lots of soybean (RR and RR2) was submitted the drying at low air temperatures of 35, 45, and 55 °C until the grains reached water content of 12% for cold storage at 10 and 20 °C, over two months. It was determined the physical and physical-chemical quality of soybean grains before and after drying and during the time in storage. The best option of preprocessing and storage strategy to obtain soybean flow and quality in high-capacity storage and handling unit was the combined drying (SSS1, SSS2, SSS3) and dry-aeration storage systems. The soybean grains harvested at high water contents submitted to drying at low temperatures and stored under artificially refrigerated conditions presented better grain quality over storage time but increased the operational drying time, hindering the flow of grain mass.     

Improvement in Storage Stability of Infrared-Dried Rough Rice

Infrared radiation heating has a promising potential in improving drying rate and food safety, but its effect on the storage stability of rough rice is not known. The objective of this study was to develop an infrared drying (IRD) method to improve the storage stability of rough rice during storage. The effects of IRD on the physicochemical properties of stored rough rice were compared with those of hot air drying (HAD) and ambient air drying (AAD). Freshly harvested M206 rice was dried to a targeted moisture content of 16 % (d.b.) by using IRD, HAD, and AAD. The dried rice samples were then stored at 35.0?±?1.0 °C and a relative humidity of 65.0?±?3.0 % for up to 10 months. The physicochemical and cooking properties of rice samples were periodically determined over the storage duration. Compared with AAD, the yellowness index, water uptake, and volume expansion ratio of the rough rice dried with IRD and stored for 4 months were reduced by 26.3, 76.3, and 14.5 %, respectively. After 10 months of storage, the change in hardness of cooked IR-dried rice was significantly reduced by 22 % compared to that of samples dried with AAD. IRD likely caused a slight denaturation of protein and annealing of starch that was located on the surface layer of rice kernels, resulting in decreased gelatinization temperature, enthalpy, and viscosity, and reduced the changes in microstructure, but retained cooking characteristics after storage. Therefore, IRD is recommended as a promising technique that achieves high rice drying efficiency and improved storage stability.     

实仓储藏初期稻谷霉菌带菌量和挥发性成分的变化规律研究

籼稻谷7月收获后使用高大平房仓储藏,分别采用平板计数法和顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME-GC-MS)研究储藏初期(2017年8月至2018年2月)稻谷霉菌带菌量及挥发性成分的变化规律。结果表明:从2017年8月入储到次年2月,稻谷粮温呈现出与气温、仓温相一致的下降趋势;稻谷水分在储藏期存在波动,但均低于籼稻安全储藏水平上限(13.5%);稻谷初始霉菌带菌量为4.67 lg cfu/g,储藏至11月时降至3.00 lg cfu/g,继续储至次年2月时变化不大;稻谷挥发性成分中,酯类检出种类及含量在11月时明显增加,但次年2月又大幅下降,壬醛在储至次年2月时含量明显增加。     

水分对低温储藏优质稻品质的影响

为改善优质稻储藏入库前水分含量,本研究以不同水分梯度(11.5%、12.5%、13.5%、14.5%、15.5%、16.5%)的优质稻分别放入15℃和20℃进行模拟储藏。研究储藏过程中其出糙率、整精米率、黄粒米、垩白粒率、大米糊化特性以及大米品尝评分等加工及蒸煮品质变化情况。结果表明:含水量为13.5%～14.5%范围内出糙率较好,含水量为12.5%～14.5%范围内整精米率较好,含水量小于15.5%黄粒米能较好的控制,垩白粒率与水分含量关系不大,优质稻储藏半年即达到最佳食用品质且偏高水分优质稻食用品质稍好,含水量对稻谷糊化特性影响较显著,含水量较低时峰值粘度较低,含水量升高峰值粘度逐渐升高;准低温以下温度储藏优质稻,其出糙率、整精米率、黄粒米率、垩白粒率、米饭品尝评分与储藏温度无关,RVA糊化特性受温度影响较大,温度高峰值黏度变化快。     

优质籼米地下仓储藏过程中品质变化

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。