基于岭脊分析的藜麦淀粉提取及糊化特性研究

为优化藜麦淀粉碱法提取工艺,以藜麦为试验材料,采用岭脊分析法研究料液比、NaOH 质量分数和浸提时间对淀粉提取率的影响,并对藜麦淀粉的颗粒形貌、化学结构及淀粉糊化特性进行研究。结果表明,碱法提取藜麦淀粉的优化工艺参数为料液比1：5 g/mL、NaOH质量分数0.2%和浸提时间5.5 h,淀粉提取率为98.94%±0.26%;藜麦淀粉为限制性膨胀淀粉,形态多呈不规则形,具有-OH、-CH2、-CHO、C-O-C和吡喃环典型淀粉分子官能团;随静置时间增加,淀粉透光率降低,凝沉体积增加,12 h后基本稳定;藜麦淀粉糊第四次冻融循环后达到稳定状态;对淀粉凝胶质构特性分析,硬度、内聚性、弹性、胶黏性和咀嚼性5个指标都随藜麦淀粉糊浓度增加而增大;流变性分析表明藜麦淀粉糊为假塑性流体,其弹性优于黏性。该文系统研究藜麦淀粉提取工艺和糊化特性,拓展了新的淀粉资源,同时也为藜麦淀粉的生产和应用提供一定的借鉴和参考。     

长期定位条件下氮肥对小麦面粉及面条品质的影响

为了探索河北省优质专用面条小麦的适宜氮肥用量。在3年定位试验的基础上,于2019—2021年采用施氮量×品种二因子裂区设计方法,施氮量为主区(氮用量分别为0、60、120、180、240和300 kg/hm²),品种为副区(冀麦738和济麦22),研究了施氮量对小麦面粉品质、淀粉糊化特性以及面条性状等指标的影响。结果表明,氮肥可显著提高小麦产量、面粉及面条品质。面条总评分与面粉的蛋白质含量、湿面筋含量、沉淀指数、吸水率、稳定时间、拉伸面积、延展度均呈显著或极显著正相关,施氮量达180 kg/hm²以上时,面粉大多品质指标得到改善,面团弹性较好。面条总评分与面粉糊化特性指标均呈正相关,但相关性均未达显著水平,低谷黏度、最终黏度和回升值冀麦738为施氮量120 kg/hm²左右表现较优,而济麦22对氮肥不敏感,同样峰值黏度和糊化温度对氮肥也不敏感。面条总评分与面条质构指标最大拉力、拉伸面积和拉伸距离均呈显著或极显著正相关,与生熟面片的亮度L 值和黄度b 值相关性不显著,冀麦738施氮量大多在180～240 kg/hm²之间、济麦22在180 kg/hm²条件下面条质构指标及亮度较佳。面条总评分与面团的最大拉伸阻力呈负相关,因此中筋小麦品种济麦22更适宜做面条,而中强筋品种冀麦738面粉品质较高,但筋力过大,造成面条感官变差,评分降低。综合考虑小麦产量、面团品质、淀粉糊化特性、面条性状等指标,优质面条小麦较适宜的施氮量为180 kg/hm²左右,此研究结果为河北省优质小麦高产提质提供支撑。     

不同地区再生季稻米蒸煮食味品质及淀粉结构与性能差异研究

为探究再生季稻米蒸煮食味品质在不同生态区的差异,并从淀粉结构与性能角度揭示其差异机理,本试验以杂交稻甬优4149、晶两优1468为供试材料,按再生稻栽培模式分别种植于肇庆、长沙、信阳3个生态区,研究了再生季齐穗后温光条件对稻米蒸煮食味品质、RVA 谱特性及淀粉热性能和晶体结构的影响。结果表明,肇庆试验地区的再生季稻米蒸煮食味品质优于长沙、信阳,其直链淀粉含量适中,胶稠度长,糊化温度较低,总淀粉含量较高。再生季齐穗后温光条件与稻米胶稠度、糊化特性以及淀粉热性能和相对结晶度具有显著相关性。籽粒灌浆初中期的温度和光照对再生季稻米淀粉的糊化性能与热性能影响较大;淀粉的相对结晶度受中后期的日均温度影响最为显著。本研究将有助于绿色农业的可持续发展和优质稻米的生产。     

精氨酸对绵羊胴体品质、肉质特性及瘤胃细菌组成的影响

瘤胃细菌在绵羊骨骼肌脂肪酸沉积中起着重要作用。为研究精氨酸对绵羊胴体品质、肉质特性和瘤胃细菌组成的影响,探究瘤胃细菌变化与脂肪酸沉积之间的关系,利用宏基因组测序、气相色谱技术分析绵羊补饲精氨酸后瘤胃细菌组成和肌肉脂肪酸谱的变化,建立两者间的关联性。选取16只健康且体质量相近的3月龄绵羊,随机分为对照组（基础饲粮）和精氨酸组（基础饲粮+1%精氨酸）,进行90 d的饲养试验。结果表明,与对照组相比,精氨酸组绵羊的背膘厚显著降低（P<0.05）,背最长肌的亮度（L^*）值、黄度（b^*）值及剪切力值均显著减小（P<0.05）,红度（a^*）值显著增加（P<0.05）。精氨酸组背最长肌十五烷酸、十七烷酸和十七碳烯酸的含量显著低于对照组（P<0.05）,二十四碳烯酸、α-亚麻酸、二十二碳六烯酸和n-3多不饱和脂肪酸的含量显著高于对照组（P<0.05）;精氨酸组n-6/n-3多不饱和脂肪酸的比值显著降低（P<0.05）。宏基因组分析显示,补充精氨酸显著提高了瘤胃中梭菌属、月形单胞菌属、瘤胃球菌属和密螺旋体属的丰度（P<0.05）,降低了丁酸弧菌属、副拟杆菌属、解琥珀酸菌属、甲烷短杆菌属和Butyrivibrio proteoclasticus的丰度（P<0.05）。此外,精氨酸组瘤胃中丁酸的含量显著增加（P<0.05）。关联性分析显示,丁酸弧菌属与n-3多不饱和脂肪酸呈显著负相关（P<0.05）与饱和脂肪酸呈显著正相关（P<0.05）;脂肪酸含量对肉的色泽和pH值有较大的影响。综上所述,精氨酸通过降低瘤胃氢化菌的数量,减少氢化的发生,促进肉中有益脂肪酸沉积,进而改善羊肉品质。研究结果为今后通过饲粮营养干预靶向调控瘤胃细菌提高羊肉品质提供参考。     

不同制粉方式对运黑161全麦粉加工特性的影响

为探讨不同制粉方式及不同粒度对黑小麦流变学特性及加工品质的影响,将运黑161黑小麦经直接粉碎法和回添法制得的全麦粉分别过80、100、120目筛,以运黑161黑小麦面粉为对照,分析全麦粉淀粉含量、水合特性、发酵特性以及流变学特性。结果表明,直接粉碎且过80目筛的全麦粉支链淀粉含量最高,为80.18%,破损淀粉含量最低,为9.93%,溶解度、膨润力最小,分别为2.5%和3%。回添法制备的全麦粉面团发酵高度、持气率小于直接粉碎法。直接粉碎且过80目筛全麦粉的粉质质量指数最高,为59.5,形成时间和稳定时间分别为3.45和3.2 min,较接近于黑小麦面粉,且该全麦粉的阻力值、最大阻力值在醒发时间135 min时最大,用该全麦粉制作的面包感官得分最高。综上,以直接粉碎且过80目筛制备的全麦粉为原料制作的全麦面包品质较好。本研究结果为黑小麦全麦面包研发提供了理论基础。     

不同淀粉糊化及凝胶特性与粉条品质的关系

为了研究粉条加工过程中原料淀粉的糊化及凝胶特性对粉条品质的影响,该文对绿豆、红薯、马铃薯、大米和玉米等5种原料淀粉的糊化凝胶特性及其粉条品质进行了测定,并对淀粉糊化凝胶特性与淀粉粉条品质之间的关系进行探讨。结果表明:5种淀粉原料所制的粉条中,绿豆粉条的品质是较好,其次就是马铃薯粉条和红薯粉条,大米粉条和玉米粉条的品质较差;淀粉的糊化特性与粉条品质之间具有显著相关性,按显著程度的大小(P值大小)依次是:峰值黏度谷值黏度衰减值回生值、最终黏度;淀粉凝胶的硬度、弹性、黏性和咀嚼性对粉条品质的影响较大,按显著程度的大小(P值大小)依次是:硬度黏性咀嚼性弹性。在粉条加工原料选择及粉条品质改善中可以考虑用谷值黏度、回生值以及淀粉凝胶特性特征值回复性、咀嚼性和黏性作为考核衡量指标。研究结果为粉条生产中原料选择及品质改善提供参考依据。     

遮阴时期对不同小麦品种淀粉组成结构及淀粉品质的影响

为研究花前和花后弱光对不同小麦品种淀粉特性的影响,2020—2021年在西昌农科院基地设计二因素裂区试验,主区因素为品种,分别为蜀麦482、川麦39、绵麦51和昌麦34,副区因素为遮阴时期,分别为拔节-开花期(S1)和拔节-成熟期(S2),自然光强为对照(CK)。结果表明,遮阴显著抑制籽粒淀粉积累,拔节-开花期、拔节-成熟期遮阴使淀粉含量分别下降2.96和5.34个百分点,直/支比无显著变化。拔节-成熟期遮阴,A型淀粉粒(>10μm)数目、体积和表面积占比分别较CK提高0.10、4.49和5.01个百分点,α-淀粉酶活性提高36.6%,面粉降落值、糊化黏度和膨胀势降低,淀粉品质变劣;拔节-开花期遮阴降低绵麦51籽粒α-淀粉酶活性,较CK减小28.6%,淀粉糊化黏度、膨胀势和降落值显著增加,淀粉品质改善。绵麦51籽粒α-淀粉酶活性较高,是其他品种的1.55～2.61倍,淀粉峰值黏度、降落值和膨胀势分别较其他品种低948.1～1 597.8 Pa·s、108～211 s、2.95～3.88 g·g^-1,且对光照变化更敏感。相关性分析表明,降落值与峰值黏度等糊化黏...     

几种淀粉的糊化特性及力学稳定性(简报)

为探索淀粉糊化的力学稳定性,以不同来源淀粉为原料,采用快速黏度分析仪于不同搅拌速度下,研究外力作用对淀粉糊化特性的影响,为淀粉质食品的品质控制提供依据。结果表明,不同来源淀粉的黏度曲线及其力学稳定性有差异。以小麦淀粉的糊化温度最低;马铃薯淀粉糊的黏度和温度稳定性最大;马铃薯和莲子淀粉的峰值黏度较高,冷糊稳定性好;莲子淀粉的热糊稳定性差;玉米淀粉糊易于老化。外力作用对淀粉糊的黏度曲线有影响。较强的外力作用后,会导致淀粉糊的强度、黏度和糊化温度降低,改善热糊稳定性和冷糊稳定性。淀粉糊化的力学稳定性与其颗粒强度有关,较大颗粒强度的淀粉的力学稳定性较好。     

不同类型叶面肥对日光温室越冬番茄风味品质的影响

为解决日光温室冬季低温弱光导致的番茄品质下降问题,该研究以 “184”番茄为试材,采用高效液相色谱法、顶空固相微萃取法与气相色谱-质谱联用（Gas Chromatography-Mass Spectrometry,GC-MS）等技术,研究5种不同类型叶面肥对番茄果实糖酸组分及挥发性物质种类和含量的影响。结果表明：喷施硒元素液体肥显著提高了白熟期、成熟期和完熟期番茄果实蔗糖和葡萄糖的含量（P < 0.05）,硅元素液体肥显著增加了白熟期、转色期和成熟期番茄果实蔗糖的含量,氨基酸液体肥显著提高了这三个时期番茄葡萄糖含量（P < 0.05）。喷施硒元素液体肥和鱼蛋白水溶肥显著降低了成熟期番茄α-酮戊二酸、柠檬酸和苹果酸含量（P < 0.05）。 硒元素液体肥显著提高了白熟期和转色期番茄糖酸比,分别较CK增加了15.32%和12.15%（ P < 0.05）。GC-MS结果显示,各处理成熟期番茄果实共检测到71种挥发性物质,包括20种醛类、9种酮类、17种醇类、5种酯类、10种烃类和10种其他类物质。各处理中醛类含量最多,酯类含量最少。5种叶面肥均可提高醛类含量,其中硅元素液体肥处理较对照显著增加21.89%（P < 0.05）。 所有被检测出的挥发性物质包含了9种特征香气成分,主要分为花香、果香和青香3种类型,硒元素液体肥、硅元素液体肥和海藻精水溶肥处理分别较对照显著提高番茄的特征香气成分总含量7.93%、17.68%和8.33%（P < 0.05）。综上,叶面喷施硒元素和硅元素液体肥可提高番茄果实糖组分,增加挥发性醛类物质和特征香气成分,对番茄风味品质提升效果显著,可在日光温室越冬番茄生产中推广应用。研究结果为设施番茄高品质栽培提供了数据支撑和实践参考。     

不同虫态米象侵害对小麦蛋白理化和结构特性的影响

为探索不同虫态米象侵害对小麦蛋白品质的影响，该研究以米象侵害后的小麦为研究对象，对米象不同虫态（卵期、幼虫期、蛹期、成虫期）侵害后的小麦粗蛋白、尿酸、蛋白组分、湿面筋、面筋吸水量、乳酸溶剂保持力（solvent retention capacity，SRC）、蔗糖SRC、巯基（-SH）、二硫键（-S-S-）、蛋白质二级结构、面筋蛋白显微结构以及制成全麦面条的色泽和质构特性等进行测定与分析。结果表明，米象的侵害会使小麦蛋白的理化特性和形态结构变差。随着米象的生长发育，小麦籽粒中粗蛋白的含量显著上升，湿面筋、面筋吸水量，乳酸SRC、蔗糖SRC，- SH和- SS -的含量下降，小麦蛋白组分和二级结构比例发生显著变化(P<0.05)，小麦的食用品质和营养价值降低。面筋蛋白显微结构显示：随着米象在小麦籽粒内部生长发育，面筋表面粗糙程度加重，断裂面和毛刺增多，到达成虫期后，部分面筋结构已经严重断裂，无法识别。制成全麦面条后，面条的色泽加深，L*值、蒸煮损失率增大，a*值、b*值、硬度、黏附性、弹性、内聚性、咀嚼性和回复性降低。该试验结果进一步阐明了米象侵害后小麦品质的劣变机制，为小麦贮藏期间及虫蚀小麦的品质改良提供了一定的理论基础。     

Effects of LAB Fermentation on Physical Properties of Oat Flour and Its Suitability for Noodle Making

Flour was obtained from oats fermented with lactic acid bacteria (LAB) to study the effect of fermentation on the physical properties and the suitability of fermented oats for use in starch noodle production. The results showed that fermented samples had a significantly lower pH than control samples. Gel strength and amylose content initially increased and then decreased (P < 0.05) with fermentation time. The peak viscosity, breakdown, final viscosity, and setback value decreased with fermentation time. Fermented noodles showed a higher hardness and springiness. In particular, Lactobacillus plantarum (LP) induced the highest springiness, cohesiveness, gumminess, chewiness, and resilience over 12 hr of fermentation. The cooking quality evaluation indicated that fermentation improved the quality of oat starch noodles. Fermented oats resulted in noodles with low cooking loss and higher cooking weight compared to noodles made from fresh flour. The use of LP for 12 hr of fermentation time yielded noodles of the best quality.     

Lycopene bioaccessibility and starch digestibility for extruded snacks enriched with tomato derivatives

To improve the nutritional value of energy-dense extruded snacks, corn grits were replaced with tomato paste and/or tomato skin powder at ratios of 5, 10, and 20% and extruded to make expanded snack foodlike products. Using a model digestion system, lycopene bioaccessibility and uptake from the snacks into Caco-2 cells were determined. The digestibility of the starch, the main nutrient component of the snacks, was also investigated. While extrusion cooking reduced the lycopene content of the snacks, the proportion of bioaccessible lycopene increased. Lycopene uptake by the Caco-2 cells from the extruded snacks exceeded that of the control in which the lycopene was not extruded, by 5% (p < 0.05). The digestibility of starch in the snacks varied depending on the type of tomato derivative and its concentration. Optimization of the extrusion cooking process and the ingredients can yield functional extruded snack products that contain bioavailable lycopene.     

豌豆粉添加对米粉品质特性的影响

为了提高米粉的营养价值,本研究将不同粒径的豌豆粉添加到米粉中,分析不同粒径及添加量(0%、7.5%、15%、30%)对大米粉粉质特性及米粉蒸煮、质构和感官特性的影响。结果表明,添加豌豆粉可以增加米粉中蛋白质的含量,添加30%豌豆粉后米粉的蛋白质含量为原米粉的1.73倍。豌豆粉的添加降低了米粉的峰值黏度、最终黏度和回生值,提高了米粉冷糊稳定性,使米粉不易老化。随着豌豆粉添加量的增加,米粉的硬度与蒸煮损失逐渐增大,感官品质降低。豌豆粉的粒度对米粉品质影响较大,当豌豆粉添加量相同时,添加200目豌豆粉的米粉蒸煮损失比添加80目豌豆粉降低9.08%~20.73%;感官评价总分提高1.35%~10.43%。综上,通过降低豌豆粉的粒度可以制备出豌豆粉添加量为30%的品质较好的米粉。本研究结果为营养健康型米粉的开发提供了一定的理论基础。     

Production of Bihon-type Noodles from Maize Starch Differing in Amylose Content

Maize starches extracted from selected maize cultivars with 0.2–60.8% amylose contents were used to produce bihon-type noodles. Starch dough using a pregelatinized starch binder was prepared and extruded through a laboratory-scale extruder simulating the traditional process of making bihon in the Philippines. The normal maize starches with amylose content of ≈28% were successfully used for bihon-type noodle production, but waxy maize starches with 0.2–3.8% amylose content and high-amylose maize starches with 40.0–60.8% amylose content failed to produce bihon-type noodles. Viscoamylograph profile parameters and swelling volume are significantly correlated to amylose content of maize starch samples evaluated. These physicochemical properties may be used to indicate that the starch samples at normal amylose levels may be used for bihon-type noodles. Starch noodles produced in the laboratory were not significantly different in terms of either cooking quality or textural properties from two commercially produced maize noodle samples, except for adhesiveness. The laboratory process and fabricated extruder can be used to produce bihon-type noodles.     

Extrusion and Characterization of Starch Films

Starch plasticized with water, glycerol, and stearic acid was extruded and sheeted into films 0.4–0.6 mm thick. The ingredients were extruded in a conical twin‐screw extruder at a temperature profile of 50–120–120–120°C and a screw speed of 45 rpm. The effects of glycerol, water, and stearic acid on selected physical and functional properties of the films were studied. The tensile strength, tensile strain at break, and Young's modulus were 0.23–2.91 MPa, 45.79–90.83%, and 2.89–37.94 MPa, respectively. Differential scanning calorimetry thermograms exhibited two glass transitions and multiple melting endotherms, including that of amylose‐lipid complexes formed during extrusion. The enthalpy of gelatinization of starch in the extruded films was 0.7–4.1 J/g and was dependent largely on the plasticizer content. Fourier‐transform infrared spectra revealed significant interactions between the starch and plasticizer but the peaks shifted to higher wave numbers with increasing glycerol content. During extrusion in the presence of glycerol, the A‐type crystalline structure of starch was transformed to B‐type. It also was observed that the V_h crystallinity increased with increase in glycerol content due to tight packing of starch chains. The water vapor permeabilities of the starch films were 12.3–19.9 g·mm/hr·m²·kPa.     

Effects of Inorganic Phosphates on the Thermodynamic,Pasting, and Asian Noodle‐Making Properties of Whole Wheat Flour

The effects of four inorganic phosphates on the thermodynamic and pasting properties of whole wheat flour as well as color, cooking quality, textural properties, and structural characteristics of whole wheat noodles were studied. The addition of phosphates increased the gelatinization temperature and enthalpy of melting of starch in whole wheat flour. Rapid visco analysis showed that all phosphates significantly increased whole wheat flour peak viscosity and final viscosity. Moreover, the whole wheat noodles prepared with disodium phosphate, trisodium phosphate, and sodium tripolyphosphate (STPP) exhibited brighter appearance, and the use of STPP and sodium hexametaphosphate reduced the cooking loss of whole wheat noodles. Texture profile analysis of cooked noodles revealed that the addition of phosphates significantly decreased the hardness and slightly increased the springiness, cohesiveness, and resilience. The microstructure of whole wheat noodles showed a larger degree of connectivity of the protein network and coverage of starch granules in the presence of inorganic phosphates. The results suggested that inorganic phosphates exhibited substantial effects on improving the quality of whole wheat noodles. Of the four phosphates studied, STPP appeared to be the most effective one in improving the overall properties of whole wheat noodles when they were normalized to constant phosphate content.     

Effects of Flour Particle Size and Starch Damage on Processing and Quality of White Salted Noodles

Several reduction grinding conditions were used on a Canadian Western Red Spring (CWRS) farina to yield flours of comparable protein content within three specific particle size ranges (132–193, 110–132, 85–110 μm) at three starch damage levels (3.0, 3.9, 7.0 Megazyme units). White salted noodles (1% w/w NaCl) were initially processed at a fixed absorption (32%). Dynamic oscillatory and large deformation creep measurements indicated that doughs with lower starch damage, thick or thin, exhibited lower G′ (storage modulus), higher tan δ (G″ [loss modulus]/G′) values, and greater maximum strain during creep than doughs with higher starch damage. There were no clear trends between work input during sheeting and either starch damage or particle size. Instrumental texture analysis of raw noodles showed no significant differences due to either starch damage or flour particle size. Flours with fine particle size gave cooked noodles with the best textural attributes, whereas starch damage exhibited no consistent relationship with cooked noodle texture. Cooking loss was greatest in samples with highest starch damage and coarsest particle size; water uptake was inversely related to starch damage and particle size. Experiments were repeated at adjusted water absorptions (32–36.5%) for fine and coarse flours with highest and lowest starch damage. Differences in raw noodle dough rheological properties were largely eliminated, confirming that differences noted at constant absorption were primarily due to flour water absorption. Work input during sheeting was inversely related to starch damage and was higher for fine particle size. Cooking losses were highest for higher starch damage and fine particle size. Water uptake was highest for fine particle size, but in contrast to cooking loss, was higher at lower starch damage. Textural parameters indicated superior cooking quality when particle size was finer and starch damage was lower. Flour particle size and starch damage (as indicated by water absorption) are both primary quality determinants of white salted noodle properties and, to some extent, exert their influence independently.