Heating process of soybean using hot-air and superheated-steam fluidized-bed dryers

The present work investigated drying characteristics and inactivation of urease in soybean dried by superheated-steam and hot-air fluidized beds. The value of effective diffusion coefficient, which was determined by a method of slopes, was increased with increased drying temperature and increased moisture content. Furthermore, it depended on the type of heating medium, with higher moisture diffusion for soybean dried by hot air. Inactivation of the urease enzyme in both media showed difference in rate, in which the enzymatic inactivation was faster for soybean dried in superheated steam than in hot air. For the individual heating medium, the modified first-order reaction was adequately fitted to experimental data. The rate of inactivation was found to increase as the temperature and moisture content were increased. The urease enzyme was inactivated, along with maintaining protein solubility and lysine content being in standard range, as soybean was treated at a temperature between 135 and 150 °C for the hot air and the treatment temperature could be reduced to be lower than 135 °C by using superheated steam.     

稻谷热风与真空干燥特性及其加工品质的对比研究

比较稻谷热风与真空干燥特性及对其加工品质的影响,为有效改善稻谷加工品质提供依据。通过对初始水分为26.5%的稻谷进行热风和真空干燥试验,研究热风干燥和真空干燥对稻谷的干燥特性和其加工品质的影响。结果表明:干燥温度越高,稻谷的平均降水速率越大,且真空干燥平均最大降水速率大于热风干燥平均最大降水速率;热风干燥在干燥开始后的5～10min降水速率出现最大值,真空干燥在干燥开始后的5～15min降水速率出现最大值。随着干燥温度的升高,稻谷的爆腰率上升,出糙率和整精米率下降;相同的干燥温度下,真空干燥稻谷的加工品质优于热风干燥稻谷的,其中爆腰率最为明显。对于高水分稻谷采用真空干燥可以提高稻谷的加工品质。     

Effects of inlet air temperature and spray rate of coating solution on quality attributes of turmeric extract coated rice using top-spray fluidized bed coating technique

The addition of natural antioxidants onto white rice kernel can improve its functionality. Curcuminoids that present in turmeric rhizomes possess high antioxidant activity and heat stability. The objective of this study was to investigate the effects of inlet air temperatures and spray rates of turmeric extract solution on quality attributes of the turmeric extract coated rice (TCR) using the top-spray fluidized bed coating technique. The experimental results have shown that inlet air temperature and spray rate of coating solution strongly affected the final moisture content and percentage of fissured kernel of TCR. Almost all of TCR kernels in the bed cracked when their final moisture content was lower than 11.8% wet basis. However, the head coated rice yield of fissured TCR slightly decreased from that of white rice. The color of TCR was uniform over the entire surface. Texture of cooked TCR insignificantly changed from that of uncoated sample. Increasing spray rate provided higher both total phenolic content (TPC) and total antioxidant capacity (TAC) whilst increasing inlet temperature yielded lower TPC but it did not affect TAC. Retentions of TPC and TAC of TCR after cooking remained higher than 90%.     

Rice degree of milling effects on hydration,texture, sensory and energy characteristics. Part 1. Cooking using excess water

The purpose was to assess the effect of degree of milling (DOM) on cooking kinetics, sensory attributes, and energy requirements when cooking rice in excess water. Commercial milling equipment was adjusted to produce parboiled and non-parboiled rice samples that were milled to varying DOMs, including brown rice lots having no milling. Surface lipid content (SLC) ranged from 0.15% to 0.55% for non-parboiled rice and from 0.40% to 0.95% for parboiled rice. The percentage gelatinized kernels, moisture content, peak force and sensory attributes were determined as a function of cooking duration for all samples. The cooking duration required to attain ‘well-cooked’ rice was determined, after which the energy required for cooking was measured. Within the SLC range tested, DOM did not affect cooking kinetics, texture and flavor of rice. Non-parboiled brown rice required the most energy, expressed as energy per unit mass of uncooked rice, to be cooked, followed by parboiled brown, parboiled milled and non-parboiled milled rice.     

流化床干燥对稻谷爆腰增率及微观结构的影响

对25.0%±0.3%高水分稻谷进行流化床干燥,研究在不同干燥温度、降水幅度与缓苏时间下对稻谷爆腰增率的影响,并通过扫描电镜观察稻谷在不同条件下谷粒显微结构的变化情况。结果表明:干燥温度、降水幅度和缓苏时间及干燥温度与缓苏时间的交互作用对稻谷干燥后的爆腰增率影响极显著（p<0.01）,影响顺序为:干燥温度>缓苏时间>降水幅度。65℃干燥温度,3.0%降水幅度,3 h缓苏时间条件下,稻谷内部淀粉粒排列结构疏松,横断面细胞间的淀粉粒间间隙大,局部裂纹数量多。稻谷在干燥温度45℃、缓苏时间3 h、降水幅度1.5%的条件下,稻谷爆腰增率1.0%,干燥速率1.32 g H₂O·min^-1,可在保障稻谷加工品质的同时提高稻谷干燥速率。      

糯米的不同干燥方式对米酒酿造的影响

该实验探究了烘干、阴干两种不同的干燥方法对糯米的基本理化特性、糊化特性和发酵特性的影响。结果表明,与阴干糯米相比,烘干糯米含水量低1.1%、出饭率高5.9%、粗淀粉含量高1.55%、直链淀粉含量高0.14%。两种糯米淀粉糊化曲线显示,烘干糯米体系整体黏度低于阴干糯米,具有较高的衰减值和回生值,糊化温度略微下降。对比两种糯米31℃发酵48 h后酿造的米酒,烘干糯米米酒比阴干糯米米酒总糖含量高59.3%、总酸含量高16.5%,酒精度低2.1%vol。结果表明烘干糯米对比与阴干糯米具有更优良的发酵性能。     

Processing of commercial rice bran for the production of fat and nutraceutical rich rice brokens,rice germ and pure bran

Successive sieving of commercial rice bran on the basis of particle size was performed and different fractions were obtained of which the rice brokens and rice germ fractions contained fat 33 g/kg and 207 g/kg, oryzanol 400 mg/kg and 874 mg/kg, total tocols (tocopherols and tocotrienols) 16.5 mg/kg and 87.8 mg/kg, and total phytosterols 128.7 mg/kg and 769.6 mg/kg respectively, thus indicating that these fractions are a good source of fat and nutraceuticals. The residual fat (6 g/kg) from commercial defatted rice bran contained high oryzanol content of 4.8 g/100 g, indicating that commercial defatted rice bran as a source of oryzanol. The fat from pure rice bran fraction of commercial rice bran decreased in the color value (48.5%) indicating that sieving could also improve the quality of crude rice bran oils.     

高温流化对黑米蒸煮品质的改良效果

针对黑米蒸煮难、口感差、需提前浸泡的问题,采用高温流化技术处理黑米,以改善黑米蒸煮品质。研究了流化温度、流化时间和进料速度对黑米蒸煮品质的影响,通过单因素和正交试验得到最优工艺参数为流化温度155℃,进料速度60 kg/h和流化时间60 s,并且影响黑米蒸煮品质的主要因素是温度。经高温流化处理后,黑米出现裂缝并伴随糊化的产生,从而吸水通道被打开,黑米粉的糊化特性也得到改善,结果与原料相比,处理过的黑米在40℃水温下浸泡200 min的吸水率为41.09%,增加了24%(P0.05);最佳蒸煮时间为22.83 min,缩短了4 min(P0.05);抗氧化活性没有显著变化(P0.05);黑米煮前不用浸泡,黑米饭的柔软度、黏性和综合评分显著提高(P0.05)。高温流化显著改善了黑米的蒸煮品质。     

干燥处理对稻谷吸湿产生裂纹敏感性的影响

研究了阴干、日晒、热风干燥三种干燥处理对稻谷早籼9711吸湿产生裂纹的影响,进一步证实了不同干燥处理后的稻谷吸湿产生裂纹的敏感性存在差异,阴干处理的稻谷吸湿产生裂纹的敏感性最低,热风干燥敏感性最高,低温干燥和低温储藏可降低稻谷吸湿产生裂纹的敏感性.     

稻谷干燥过程中整精米率的影响因素研究

该试验依据我国南方农村的稻谷干燥习惯,以大粒溪香优质稻品种为试材,对稻谷干燥过程中整精米率的影响因素进行研究。试验结果表明,稻谷干燥过程中不同处理对最终整精米率影响较大,不同处理之间整精米率最大相差6.8%。稻谷晾晒过程中采用篾席晾晒比水泥地直接晾晒所得整精米率高3.6%,晾晒过程中夜间存放于室外比存放于室内整精米率高2.2%,这些处理对稻谷最终含水量影响不大。     

Key factors affecting Fe density in Fe-fortified-parboiled rice: Parboiling conditions,storage duration,external Fe-loading rate and genotypic differences

The present study evaluated the key factors affecting the efficiency of iron (Fe) penetration into the endosperm in parboiled rice of different varieties. It also investigated effects of storage time on Fe bio-accessibility, rice colour and Fe retention after rinsing. Rice grains of three varieties were fortified with an increasing range of Fe-fortification rates during the parboiling process, under two typical parboiling conditions, which are ambient soaking temperature for 24 h and 60 °C soaking temperature for 6 h at neutral (6.0–6.5) and acidic pH (3.0–3.5). Soaking of paddy rice, at 60 °C in acidic water for 6 h before steaming, was found to be better for maximising the Fe concentration in white-parboiled rice than the former ambient soaking. Under this parboiling condition, adding 250 mg Fe kg⁻¹ of paddy rice, at soaking, produced the most desirable Fe concentration in white rice, ranging from 17.5 to 25.4 mg kg⁻¹ among the rice varieties tested. The concentrations of Fe in parboiled white rice exhibited an exponential increase with increasing concentrations of Fe in the soaking water in all varieties, which were linearly related to Fe concentration of brown rice (r = 0.96∗∗, p < 0.01). The colour of the parboiled rice fortified with Fe was initially light yellow, with variation among rice varieties, but it did become slightly darker after 16 weeks of storage, probably because of Fe oxidisation. This may be related to decreasing bio-accessibility after 20 weeks of storage. Storage, however, did not affect the total Fe retention after rinsing, though the retention rate was variety-dependent. Information about parboiling will provide the basis for formulating an optimal industry protocol for producing Fe-fortified-parboiled rice, which can be further refined in pilot studies on the industrial scale.     

热风干燥条件对中式腊肠微生物及质构特性的影响

采用4种不同的工艺干燥中式腊肠,通过测定干燥过程中腊肠水分含量与活度、微生物菌群数量,并采用TPA法测定不同干燥工艺加工过程中腊肠的硬度、弹性、咀嚼性等质构特性的变化趋势,分析干燥条件对腊肠质量的影响。结果表明:干燥工艺对微生物的影响差异显著(P<0.05),对产品质构特性也有很大的影响。升温干燥模式制作的腊肠微生物数量最低,但质构偏硬;先高温后低温干燥模式制作的腊肠微生物数量较高,但质构最软;五段变温干燥模式和恒温干燥模式差异不显著(P>0.05),与文献[5]的传统工艺生产的腊肠微生物特性与质构特性差异不显著(P>0.05)。三段式升温烘烤模式相对于其他干燥工艺能更好的抑制微生物生长,更适用于中式腊肠的生产。     

The bioavailability of iron fortified in whole grain parboiled rice

The present study was to evaluate the bioavailability of iron (Fe) fortified in parboiled rice grain, expressed as Fe uptake by Caco-2 cells after in vitro digestion. The bioavailability of Fe-fortified in the rice grain was closely and positively correlated with increasing concentrations of Fe in the grains of the three cultivars (r = 0.96∗∗). The uptakes of the Fe-fortified in parboiled rice milled for 120 s (34.2, 47.7 and 107 ng ferritin mg protein⁻¹ in three cultivars, respectively) were well above those of the unfortified raw (6.1, 4.9 and 5.7 ng ferritin mg protein⁻¹) or parboiled rice (4.7, 3.6 and 4.4 ng ferritin mg protein⁻¹), the high Fe rice line IR68144-2B-3-2-2 (4.0 ng ferritin mg protein⁻¹) and popular Jasmine rice cultivar KDML 105 (3.9 ng ferritin mg protein⁻¹). Increasing milling time and rinsing the Fe-fortified parboiled rice decreased Fe bioavailability, due to their negative effects on total Fe concentrations in the parboiled rice grains, but uptakes were still well above that of their unfortified raw or parboiled rice grains. Rinsing or washing the Fe-fortified and milled rice grains decreased the bioavailability to 85 ng ferritin mg protein⁻¹ in the YRF cultivar, compared to about 100 ng ferritin mg protein⁻¹ in its non-rinsed grains. Dilute acid-extractable (DAE) Fe was linearly, positively correlated with the uptake of Fe assessed by the in vitro digestion/Caco-2 cell technique (r = 0.90∗∗), which can be used as a rapid method for optimizing levels of bioavailable Fe to be fortified in the parboiled rice by parboiled-rice mills if this Fe-fortification technique should be adopted in south and southeast Asia.     

Migration of mycotoxins into rice starchy endosperm during the parboiling process

Considering the occurrence of rice contamination by mycotoxins and the increase in rice consumption, the present work had the objective of assessing the migration of mycotoxins into the starchy endosperm during the parboiling process, as to propose conditions that provide lower contamination levels. The newly harvested rice grain sample was examined for the natural occurrence of mycotoxins (aflatoxin B₁, aflatoxin B₂, deoxynivalenol, ochratoxin A, and zearalenone); only the presence of aflatoxin B₁ was found (17 ng/g). The samples were then artificially contaminated with deoxynivalenol and zearalenone, and the parboiling process was conducted according to a 2³ factorial planning with central point, having as variables the contamination level deoxynivalenol 720, 1440, and 2160 ng/g, and zearalenone 476, 952, and 1428 ng/g the soaking time (4, 5, and 6 h) and autoclave time (15, 22.5, and 30 min). Mycotoxins aflatoxin B₁ (AFA B₁), deoxynivalenol (DON), and zearalenone (ZEA) were confirmed and determined through gas chromatography. Findings showed a lower migration trend for AFA B₁ under 6 h of soaking and 30 min of autoclaving, for DON under 6 h of soaking regardless of the autoclaving time, and for ZEA under 4 h of soaking and 15 min of autoclaving. This information can contribute to the choice of process parameters that limit the migration of these mycotoxins if they happen in the raw material.     

Folic acid fortification of parboiled rice: Multifactorial analysis and kinetic investigation

Folic acid fortification of parboiled rice has been systematically studied to obtain quantitative insights into the role of key process variables. Parboiling was conducted with brown rice soaked at 70 °C for 1, 2 and 3 h with four different fortificant concentrations added and dried parboiled rice was milled for three durations (i.e. 0, 60 and 120 s). Both residual folate concentration in treated parboiled rice and pH of the soaking water after soaking stages were measured. Multifactorial model was developed to describe the residual folate retention behaviour and suggested that both soaking and milling were significant factors in folic acid fortification. The optimum soaking time was deduced to be 1.97 h. Folate retention rate followed a 1st order kinetics while the rates of natural rice hydrolysis and folate uptake were both time-dependent.     

康乃馨热风干燥特性研究

选取康乃馨为研究对象,以热风温度、风速、装载量为试验因素进行单因素试验,分析各个因素对干燥特性的影响。结果表明,3个因素对康乃馨的干燥特性影响均显著,温度越高,风速越大,装载量越少,康乃馨达到安全水分所用的时间就越短。采用3种常用的干燥模型单项扩散模型、指数模型、Page模型对试验数据进行线性回归分析和模型的拟合,得出Page模型适合描述康乃馨的干燥进程,并建立康乃馨的干燥模型。通过试验验证,Page模型的预测值与实测值的最大误差仅为6.7%,很好地描述了康乃馨的干燥进程。     

Innovative production of multistrain synbiotic product using Thai-pigmented rice and rice bran oil

This study found that the isolated probiotics Lactobacillus paracasei KUKPS6201, L. acidophilus KUKPS6107, L. reuteri KUKPS6103, L. rhamnosus KUKPS6007, L. salivarius KUKPS6202, Bacillus coagulans KPSTF02 and Saccharomyces boulardii KUKPS6005 had high potential for probiotic properties. All strains had antibacterial activity and high antioxidant activity of 1.654 ± 0.017 mg Trolox mL⁻¹ probiotic extract. The selected strains could survive in a simulated gastrointestinal tract under anaerobic conditions and showed no haemolytic activity. Furthermore, the probiotic strains were strongly auto-aggregated and also showed co-aggregated ability with pathogenic bacteria. The probiotic microorganisms demonstrated high ability to adhere to Thai-pigmented rice grains. The results of analysis of these probiotics showed that Riceberry rice bran oil was an excellent prebiotic. A synbiotic product containing Thai-pigmented rice grains (cultivar Riceberry, Luem Pua and Black Jasmine) and rice bran oil was produced. After 8 weeks of storage, the viability of the probiotics in terms of multistrains was 7.36 ± 0.04 log CFU g^–1 (85.78% survival rate). Microbiological safety testing indicated that the amounts of contaminants were acceptable. This study provided the first scientific report on the feasibility of applying Thai-pigment rice, rice bran oil and mixed-culture probiotics as a novel functional synbiotic product.     

大米基本成分与米发糕品质间相关性探讨

对10种大米的基本成分及其所加工成的米发糕品质进行分析,并对大米基本成分与米发糕的感官品质、质构特性之间相关性进行探讨。结果表明:影响米发糕品质的主要因素是大米直链淀粉含量、蛋白质含量、水分含量,其中直链淀粉含量对米发糕品质的影响最大;大米的直链淀粉含量与米发糕的比容、结构、回复性呈极显著正相关,与米发糕的外观形状、硬度、咀嚼性呈显著正相关;大米的蛋白质含量与米发糕的外观形状、硬度和咀嚼性呈显著负相关;大米的水分含量与米发糕的弹性呈显著负相关。     

间歇干燥及缓苏对高水分稻谷干燥品质的影响

对高水分稻谷进行了间歇干燥,研究干燥段数和缓苏温度对稻谷干燥品质的影响,并应用隶属度分析法对干燥品质进行综合评价。结果表明,间歇干燥可缩短干燥时间,与连续干燥40℃缓苏组相比,4段60℃缓苏组的干燥时间缩短了26.36%。间歇干燥可显著地降低干燥后稻谷的爆腰率,提高整精米率。高温缓苏(50、60℃)时,缓苏温度对整精米率影响优于干燥段数。热风干燥后稻谷的脂肪酸值增加,发芽率降低。隶属度分析法得出优化后的干燥条件为:干燥段数为2段,缓苏温度为60℃,综合分为最大值0.80。     

富硒大米粉预糊化及其复配代餐粉的研制

以富硒大米为原料,采用喷雾干燥、真空冷冻干燥和滚筒干燥3种技术制备预糊化大米粉,考察不同预糊化加工方式对大米粉硒保存率及品质的影响,并以预糊化富硒大米粉为主要原料制备代餐粉。结果表明,预糊化大米粉硒保留率从低到高的顺序为:喷雾干燥<冷冻干燥<滚筒干燥,糊化度从低到高的顺序为:原料米粉<滚筒干燥<冷冻干燥<喷雾干燥。采用滚筒干燥制备的富硒大米粉(硒含量192. 08μg/kg)糊化度低、硒保留率最高(48. 82%)、呈片状结构,在冲调过程中易分散均匀。从硒含量、营养品质、溶解稳定性综合考虑,含硒大米代餐粉较适宜的配方为(g/100 g):富硒大米粉50,红枣粉5,黑芝麻粉0. 5,葛根粉5,山药粉24. 5,红豆粉5,薏米粉5,糙米粉5。