酸湿热处理对米粉性质的影响研究

本文在实验室条件下采用酸湿热处理米粉样品,测定处理前后米粉的化学组成变化、颗粒形貌、结晶性质、红外图谱、热力学性质、糊化性质和消化特性。研究表明,经过酸湿热处理后的米粉蛋白质含量减少较多,其它的粗脂肪、还原糖变化不大。显微结构分析得出米粉保持原有的团粒结构,但偏光十字稍微变得模糊,颗粒的有序结构遭到一定破坏,少数淀粉脐点处出现凹坑。红外图谱变化不大,结晶度变小。处理后米粉的起糊温度升高,糊的峰值粘度降低,吸收焓减小。酸湿热处理可以一定程度下提高米粉中慢速消化淀粉(SDS)的含量。     

湿热处理对玉米淀粉性质的影响

研究了湿热处理对不同直链淀粉含量的普通玉米淀粉?高直链玉米淀粉和蜡质玉米淀粉性质的影响。试验证明,经湿热处理后,三种玉米淀粉的颗粒形状都没有发生明显的变化,偏光十字也没有消失,但表面出现一些裂纹;湿热处理不会改变三种玉米淀粉的晶型,但经湿热处理后玉米淀粉的晶体结构变强,糊化温度提高,糊黏度降低。     

湿热处理对淀粉性质的影响

水分含量为30％的高链玉米淀粉在100℃处理12h。通过研究淀粉的性质发现，湿热处理后淀粉的颗粒形状保持不变，但表面出现了凹坑；主要衍射峰强度增加，结晶度为44．65％，比原淀粉大2．51％；To、Tp、Tc分别比原淀粉相应的温度高14．02、18．81、6．87℃，而△H却比原淀粉小1．08cal/g：湿热处理淀粉的膨胀度和溶解度变小；淀粉的Brabender粘度曲线几乎为一直线；酸水解前7d，湿热处理淀粉水解率比原淀粉大，之后水解率小于原淀粉，而酶水解到第3d，原淀粉水解率大于湿热处理淀粉。淀粉性质的变化说明湿热处理使淀粉内部结构发生变化，特别是无定形区的直链淀粉的结合产生了不同稳定性的新的结晶。     

湿热处理对损伤淀粉理化性质的影响研究

以郑麦366小麦淀粉为原料对其进行脱脂处理和球磨处理,通过测定相关理化指标,研究湿热处理对脱脂前后损伤淀粉的改性作用.研究表明湿热处理可以降低损伤淀粉含量,降低淀粉糊黏度,降低溶解度和溶胀势,提高糊化温度,降低糊化焓,促进淀粉分子的重结晶.     

湿热处理对山药粉理化及结构性质的影响

为了研究湿热处理对山药粉理化和结构性质的影响,在90和110℃下,分别对水分含量15％、25％和35％的样品进行9h湿热处理,并对处理后的山药粉进行了溶胀性、糊化特性、热力学特性、结晶程度以及红外光谱的测定.结果表明,湿热处理使山药粉溶解度增加,在处理条件为90℃水分含量25％时,溶解度升至9.88％,而膨胀力由3.9...     

湿热处理对玉米淀粉性质的影响

利用烘箱和高压灭菌锅对水分含量分别为10%、18%、25%、30% 的玉米淀粉在121℃处理5h,研究淀粉性质发生改变的情况。实验结果表明,玉米淀粉经湿热处理后,淀粉颗粒中心出现凹坑,颗粒结晶程度增加,淀粉的糊化温度上升,糊液黏度降低,在相同的处理条件下,利用高压灭菌锅处理对淀粉的性质影响更为显著。湿热处理对淀粉的性质产生明显影响。     

不同湿热处理方法对玉米淀粉性质的影响

利用烘箱和高压灭菌锅对水分含量为25%(w/w)的玉米淀粉在121℃处理5h,研究淀粉性质发生改变的情况.试验结果表明,玉米淀粉经湿热处理后,淀粉颗粒中心出现凹坑,颗粒结晶程度增加,淀粉的糊化温度上升,糊液黏度降低,膨胀能力升高,溶解度下降.在相同的处理条件下,利用高压灭茵锅湿热处理对淀粉的性质影响更为显著.     

微波湿热处理对薏苡仁淀粉性质的影响

以薏苡仁淀粉为原料,采用微波辐射不同湿度的淀粉进行不同时间的湿热处理,研究不同条件的微波湿热处理对薏苡仁淀粉性质的影响。研究表明,微波湿热处理后,与原薏苡仁淀粉相比,处理后淀粉的直链淀粉质量分数增加17.48%,其缓慢消化淀粉质量分数增加12.37%,其抗性淀粉质量分数增加8.66%,其糊化温度升高2.00℃,其热焓值下降7.56 J/g,处理后淀粉的溶解度、膨胀度、峰值黏度、谷值黏度、最终黏度、崩解值、回生值均降低;处理后淀粉的晶型不变仍为A型,相对结晶度降低9.39%。对试验结果进行相关性分析,发现多数淀粉性质与处理时间及湿度呈显著相关性,且处理湿度对淀粉的影响大于处理时间。     

湿热协同海藻酸钠处理对普通玉米淀粉物化性质的影响

为研究湿热协同海藻酸钠处理（heat moisture treatment combined with sodium alginate,HMT-AG）对普通玉米淀粉（normal corn starch,NCS）性质的影响,以单独湿热处理（heat moisture treatment,HMT）为对照,探讨了HMT-AG对NCS糊化、热力学性质、结晶结构及凝胶性质等的影响。湿热处理条件分别为水分质量分数15%～35%、处理温度80～120 ℃、处理时间1～15 h。结果表明：HMT-AG使NCS的成糊温度升高,衰减值、回生值、糊化焓显著降低（P＜0.05）;HMT或HMT-AG均不改变NCS的X射线衍射峰型,水分质量分数大于25%的HMT显著降低了NCS的相对结晶度（relative crystallinity,RC）（P＜0.05）,但同条件HMT-AG显著升高了NCS的RC（P＜0.05）;当以水分质量分数25%、120 ℃条件处理6 h时,与HMT相比,HMT-AG对NCS黏度、起始糊化温度、凝胶硬度的降低影响更为显著（P＜0.05）。     

湿热处理对高粱淀粉理化性质的影响

以高粱种子为原料制备高粱淀粉,在4个不同含水量(20%、25%、30%和35%)条件下,110℃湿热处理16 h对淀粉进行改性,进而分析湿热处理对其理化性质的影响。结果表明:湿热处理没有改变高粱淀粉典型的A型晶体结构,但相对结晶度从21.1%显著增加到36.6%;湿热处理后,淀粉颗粒表面形态有明显变化,吸水性和淀粉糊化温度的增加也与处理的水分含量呈正相关,最高值分别为HMT-35的1.7 m L/g和76.7℃;同时淀粉的溶解度和膨胀度、吸油性、峰值黏度和热焓变值(ΔH)随着处理水分含量的提高而显著降低。证明湿热处理能有效改变高粱淀粉结构和理化性质,可以提高其热稳定性,扩大其在食品工业及其他行业的应用范围。     

乳酸湿热处理改善大米粉性质及粉条品质的研究

主要研究乳酸湿热处理对大米粉性质及其干粉条和湿粉条品质的影响。以水磨籼米粉为原料,通过不同浓度乳酸、湿热以及乳酸与湿热联用的方法对米粉进行处理,研究不同条件下制备的大米粉的糊化特性、溶解度、膨胀率以及干粉条和湿粉条的蒸煮品质和质构品质。实验结果表明:乳酸湿热处理对大米粉糊化特性影响显著,大米粉通过湿热处理、乳酸处理、乳酸湿热联用处理后,大米粉的峰值黏度、谷值黏度、衰减值、最终黏度、回生值都有所降低。在乳酸处理(pH=4)时,峰值黏度最高。乳酸湿热处理对大米粉的溶解度和膨胀度都有一定的影响,与原样相比,被处理过的样品其溶解度、膨胀度都逐渐降低。在粉条蒸煮品质测定中,乳酸处理(pH=4)后,干粉条和湿粉条的断条率、蒸煮损失率都达到最低。在粉条质构品质测定中,经过湿热处理、乳酸处理和乳酸湿热联用处理三种方法处理以后,湿粉条的硬度、咀嚼性均有所下降,在乳酸处理(pH=4)时,湿粉条的弹性达到最大;在湿热处理、乳酸处理和乳酸湿热联用处理中,干粉条的黏度有所下降,在乳酸(pH=4)时,干粉条的弹性达到最大。最终结果:在乳酸处理(pH=4)时,对改善大米粉性质及粉条品质的效果是最优的。     

Effects of plasma-activated water and heat moisture treatment on the properties of wheat flour and dough

Plasma-activated water (PAW) production and use is an emerging technology for enhancing product safety, extending shelf-life and quality retention, and promoting sustainable processing. At present, it has generated considerable attention for applications to starch and flour modification. This work presents an innovative approach to wheat flour (WF) modification using PAW and heat-moisture treatment (HMT), and compares this approach with distilled water (DW) treatment. As expected, PAW and HMT promoted flour granule clustering, increasing particle size. These treatments accelerated molecular interactions between wheat starch and non-starch components (e.g. proteins and lipids), which eventually increased resistant starch (RS) content. Addition of modified flour (30 g) to WF positively affected its rheological properties, and closely bound water content of the dough. The gluten protein network structure in the dough suffered varying degrees of damage. In conclusion, our results showed that PAW and HMT may provide a novel beneficial method for modifying wheat flour during food processing to obtain viscoelastic wheat flour products with nutritional functions.     

Sorption equilibrium moisture and isosteric heat of cold plasma treated milled rice

To promote industrial adoption of cold plasma as a sustainable and safe processing technology for rice, data on equilibrium moisture content (EMC) for cold plasma treated milled rice of five Chinese varieties were collected by a gravimetric method at 11–96% equilibrium relative humidity (ERH) and a temperature range of 15–35 °C. Nine models were fitted well to the sorption data, with the modified Guggenheim–Anderson–deBoer equation (3-MGAB), modified Henderson equation (MHE), and a polynomial equation being the best fits. At a constant ERH, the EMC was negatively correlated with temperature, whereas there was a strong effect of temperature on the sorption isotherms of the milled rice. Initially, the isosteric heats of sorption for the cold plasma treated rice decreased rapidly with increasing sample moisture content (MC); however, when MC was higher than 15% of the wet basis (w.b.), further increases in MC caused a slight decrease in heat sorption values. The heat of vaporization of the milled rice approached the latent heat of pure water at a moisture content of ~17.5% w.b., which was ~2500 kJ/kg. The isosteric heat of sorption values of the milled rice predicted by the modified Chung-Pfost equation (MCPE) and MHE models negatively correlated with temperature. At 70% ERH, the safe-storage MC of the cold plasma treated rice were ≤14.5% w.b. at 25 °C. In comparison to the untreated milled rice, the cold plasma treated rice with 120 W for 20 s and 60 s significantly decreased the water contact angle and increased kernel broken index, without significantly changing the appearance quality of milled rice. The cold plasma treated rice with 120 W-20 s had insignificantly higher EMC than that of 120 W-60 s at the studied temperature range. This study demonstrates that helium cold plasma treatment insignificantly changed hygroscopic property of milled rice whilst maintaining the appearance quality.     

Vc氧化对糯米粉特性影响的研究

以不同品种糯米为原料,以抗坏血酸(Vc)为氧化剂制成氧化糯米粉。对糯米粉和氧化糯米粉的特性进行测定和比较。结果表明:与原糯米粉相比,氧化糯米粉的糊化温度升高7.95℃～10.55℃,峰值黏度升高26%～170%,溶解度和膨润力下降,冻融稳定性增强。     

Physicochemical properties of pressure moisture treated (PMT) and heat moisture treated (HMT) starches

Physicochemical properties of pressure moisture treated (PMT, 550 MPa, 10 min) and heat moisture treated (HMT, 100 °C, 10 h) starches were investigated. Effects of PMT and HMT were different depending on starch type. PMT starches showed dramatic changes in moisture sorption isotherm, pasting properties, thermal characteristics, solubility and swelling power (at 90 °C), and in vitro digestibility. The most dramatic difference between PMT and HMT starches was amylopectin melting transition, i.e., broadening in PMT and shift to high temperature in HMT starches. Moreover, B- and C-type starches revealed the more increase in amylopectin melting enthalpy than A-type starch. Both PMT and HMT did not increase the crystallinity but reorganized the amorphous area to compact, resulting in lower rapidly digestible starch and higher slowly digestible starch than those of native starches. Consequently, PMT changed the digestibility and physicochemical properties of starches with different modes of action compared with HMT.     

超微粉碎处理对糙米粉理化性质的影响

研究了超微粉碎处理对糙米粉理化性质的影响。选取经过超微粉碎频率0~40处理的糙米粉为原料,以损伤淀粉含量、粒度分布、水合特性、糊化性质为分析指标,比较不同超微粉碎强度处理的糙米粉物理化学性质的差异性。结果显示,随着超微粉碎频率的增大,糙米粉损伤淀粉含量从7.84%上升到14.58%;粒径D[4,3]从171μm下降到11μm;吸水指数、膨胀势上升,水溶性先上升后下降。RVA结果显示,糙米粉的峰值粘度、谷值粘度、崩解值、最终粘度、回生值均上升,初始糊化温度下降。扫描电镜结果显示,淀粉颗粒破碎、断裂形成许多无规则小碎片,且表面有凹坑。     

Rheological properties of rice flour treated with mild solutions of citric acid

Effects of milling methods and organic acids treatments on rheological properties of rice flour were investigated. The average particle-size of wet-milled rice flour was lower and showed lower pasting temperature, peak viscosity, and storage modulus values than those of dry-milled rice flour. Wet-milled rice flour treated with citric acid showed significantly low viscosity and viscoelastic properties, as the concentration of citric acid increased, whereas wet-milled rice flour treated with acetic acid was not significantly affected by the acetic acid concentration. Rheological property of baekseolgi (Korean rice cake) made with wet-milled citric-acid-treated rice flour showed a similar trend in viscoelasticity, wherein citric acid treatment lowered the hardness of the rice. However, cohesiveness increased with increasing citric acid concentration. Overall, milling method affected the particle size, which influenced the viscosity and heat stability, whereas citric acid treatment affected the rheological properties of rice flour. These results are expected to contribute to the development of an appropriate method for rice flour application.     

热处理在稻谷及大米贮藏与加工中的应用研究进展

文章介绍了在稻谷及大米贮藏与加工中常用的热处理方法,阐述了热处理对稻谷中害虫、微生物、酶及其品质的影响,并分析了热处理对稻谷及大米的不利影响及其预防措施。     

马铃薯全粉平衡水分吸附等温线与吸附等热研究

采用静态称重法在温度10～35℃、相对湿度11%～96%范围内测定了五种马铃薯全粉的平衡水分/平衡相对湿度(EMC/ERH)数据,确定了多项式方程、修正3参数Guggenheim-Anderson-de Boer(MGAB)、修正Halsey(MHAE)、修正Oswin(MOE)为适合的等温线拟合方程,采用多项式EMC方程分析马铃薯全粉的安全储运最大允许的含水率,在25℃、RH60%条件下,绝对安全水分是10.05%;在25℃、RH 70%条件,相对安全水分是12.64%。采用MHAE分析马铃薯全粉水分吸附等热,随着含水率增加到17.5%,马铃薯全粉水分吸附等热则以抛物线形式快速地减少,之后随着含水率增加,水分吸附等热则减少缓慢。在含水率22%,马铃薯全粉水分吸附等热接近纯水的吸附等热。