云南软米品质特性比较研究

软米是云南特有的优质米资源,但目前对软米的品质特征仅限于定性的描述。因此,为更有效地利用云南省这一独特的优质米资源,本研究将云南软米与粘米、糯米进行外观品质、碾磨品质、蒸煮食味品质以及营养品质的比较研究。经方差分析表明,3种类型的稻米在粒长、粒宽、长/宽、直链淀粉含量、胶稠度以及蛋白质含量上存在显著差异,尤其在直链淀粉含量上差异极显著(F=119.485**)。指出可以把粒型>3.0,直链淀粉含量7.1%~15.0%,胶稠度45~80 mm,蛋白质含量<9%,并且亲本的系谱中有云南软米地方品种的材料初步鉴定为软米材料。并提出一些加快云南软米资源研究及育种方向的建议,旨在为加快软米育种与生产提供参考。     

Effect of extrusion cooking temperature on the microstructure of extruded pellets

ABSTRACT:   The microstructure of extruded pellets (EP) for fish under various extrusion cooking temperatures was studied by using a twin-shaft extruder. As the extrusion cooking temperature increased, the expansion rate increased and the bulk density of EP decreased. The liquefaction of the material started because of the increase in inner material temperature, the decrease in inner material pressure, and the decrease in main motor amperage. Thus, the microstructure of EP changed depending on the extrusion cooking conditions, that is, the extrusion cooking temperature effected greatly the liquefaction of the material. Generally, when the extrusion cooking temperature increased, the expansion rate increased, but a suitable temperature was found for a maximum expansion rate. The microstructure of the EP was caused by the liquefaction of the material and the microstructure effects on the function of EP. For example, the water holding capacity was affected by the inner bubble structure of an EP. These functions affect the character of the feed. EP produced under suitable conditions can have additional functions for feed.     

Chemical, physical and sensory changes of small abalone meat during cooking

ABSTRACT:   Small abalone meats were heated at 80°C and 98°C for 0–120 min and the differences in chemical, physical and sensory changes of the cooked meats were investigated. The decrease in moisture and weight and the increase in browning and Hunter's b -value were relatively higher for cooking at 98°C than at 80°C. After cooking for 20–120 min, the total amount of adenosine triphosphate and its related compounds on a dry weight basis decreased by 17–27% at 80°C and by 30–39% at 98°C; the total amount of free amino acids on a dry weight basis changed insignificantly at 80°C but decreased by 22–35% after cooking at 98°C. The meats cooked at 80°C were higher in cutting force whereas the levels in the samples cooked at 98°C did not decrease until samples had been cooked for 60 min. The hydroxyproline content showed little change during cooking except for in samples cooked at 98°C for 120 min, in which the content was found to be low. The extended cooking at 80°C improved the acceptability of small abalone meat, whereas only the acceptability score of aroma increased significantly for cooking at 98°C.     

关于秸秆氧化气化气做炊事燃气的商榷

阐述了秸秆氧化气化工艺原理与特点。并指出作为炊事燃气供应系统应具备的特点和要求,与干馏气方法相比,秸秆氧化气化气做炊事燃气具有不安全、费用高等不容忽视的诸多弊端。建议拟以秸秆氧化气化气做炊事燃气的有关部门慎重考虑,应利用经典的干馏气做炊事用气。     

Quality evaluation of commercial chile-based salsas

A standardized extrusion cooking process was developed for production of a high protein weaning food based on peanuts, maize and soybeans. Major factors evaluated included the effects of blend formulation, extrusion temperature and feed moisture content on ease of extrusion and product quality characteristics. Results showed bulk density and hardness increased while expansion index decreased with increase in feed moisture content. At a fixed range of feed moisture content, product bulk density and firmness decreased while expansion index increased with increasing extrusion temperature. For ease of extrusion and best product quality in terms of sensory attributes and cooking properties, the following extrusion parameters were established for a blend formulation of 75% maize, 10% peanut and 15% soybean: feed particle size of 300–400 m extruded using a screw speed of 500 rpm, with a feed rate of 4.6 kg/min, feed moisture content of 16–18%, and extrusion temperature of 100 ,°C–105,°C. Pair-wise comparison of the sensory attributes of porridges prepared from milled samples of the weaning foods showed significant differences between extruded products and existing traditional counterparts, with very high scores for all sensory attributes of the extruded products, especially extruded raw (non-roasted) blend samples. In the Home-Use-Test, at least 92% of respondents in two out of the three major ecological zones of Ghana placed overall sensory and functional characteristics of extruded raw blend samples as highly acceptable. About 7% of respondents scored sensory and functional quality attributes as acceptable.     

灌浆成熟期温度对水稻籽粒淀粉合成关键酶活性及品质的影响

 选用蒸煮食味品质不同的3个粳稻品种，利用温室高温和自然常温，研究了灌浆成熟期温度对水稻籽粒淀粉合成关键酶活性及蒸煮食味品质的影响。结果表明，灌浆成熟期高温条件下，水稻籽粒蛋白质含量提高，直链淀粉含量和味度值降低，劣质品种提高或降低的程度大于优质品种；RVA谱特性对灌浆成熟期温度的反应因品种和特性而异；灌浆过程中，籽粒ADPG焦磷酸化酶、可溶性淀粉合成酶和淀粉分支酶活性随灌浆进程，酶活性逐渐增加，达到峰值以后，酶活性又逐渐下降，呈单峰曲线，但不同品种酶活性达到峰值的时间和同一时期的酶活性大小有差异；ADPG焦磷酸化酶和可溶性淀粉合成酶的活性表现对温度的影响反应较为迟钝，而淀粉分支酶活性表现对温度变化的反应较为敏感，温度过高过低都降低该酶活性。     

Effects of extrusion cooking on some functional properties of soy-sweet potato mixtures – A response surface analysis

Mixtures of defatted soy flour and sweet potatoes wereextruded at 0:100, 25:75, 50:50, 75:25 and 100:0ratios in an Insta-Pro 600 single screw extruderoperated at 180, 200, 220 rpm.Oil (3–5%) was added into the mix before extrusion.A 5×3² fractional factorial central compositeresponse surface design was adopted forinvestigating the variables: feed composition, % oil,and screw rotation speed (RPM). Percent oil andscrew speed were randomly investigated at threelevels, while feed composition was randomlyinvestigated at five levels. Effect of extrusioncooking on functional properties: bulk density,expansion ratio, water absorption and solubilityindices and trypsin inhibitor were assessed.Results showed that feed composition and screw speedhad strong influences on the process. The effect ofadding oil, into defatted soybean significantly(p<0.05) affected only trypsin inhibitor content.High extrusion temperature (>130 ^°C), andaccompanying high shear, were the result of thenon-pasting nature of the extrudate. Therefore theproducts may have limited uses.     

Evaluation of the Lime-Cooking and Tortilla Making Properties of Quality Protein Maize Hybrids Grown in Mexico

Eleven experimental and three commercial white quality protein maize (QPM) hybrids and two regular endosperm controls were planted at Celaya, Guanajuato, Mexico with the aim of comparing grain physical characteristics, protein quality, lime-cooking and tortilla making properties. All genotypes were planted under irrigation using a density of 80,000 plants/ha and fertilized with 250 kg N-60 P-60 K per hectare. When compared with the controls these QPM genotypes had lower test (77.4 vs. 76.5 kg/hL) and 1,000 kernel weights (327 vs. 307 g), softer endosperm texture (2.5 vs. 1.8 where 1 = soft, 2 intermediate and 3 hard endosperm), lower protein (10.0 vs. 8.0%), higher nixtamal water uptake after 30 min lime-cooking (50.0 vs. 53.1% moisture) and lower pericarp removal scores. The lower thousand-kernel weight and softer endosperm texture observed in the QPM genotypes lowered the optimum lime-cooking time as estimated with regression equations. Most QPM genotypes had higher amounts of lysine, tryptophan and albumins/globulins when compared with the controls. QPMs HEC 424973, HEC 774986 and HEC 734286 had the best grain traits for nixtamalization and therefore the best potential for industrial utilization. The commercial use of these QPM hybrids should benefit Mexicans who depend on tortillas as the main staple.     

不同氮素水平下水分处理对北方粳稻蒸煮品质的影响

以不同类型水稻品种为材料,研究了中肥节水灌溉、高肥节水灌溉、高肥正常灌溉、中肥正常灌溉处理对粳稻蒸煮品质的影响。结果表明不同类型品种胶稠度不同:弯穗型品种>杂交稻>半直立穗型品种>直立穗型品种;施氮量对胶稠度的影响差异接近显著水平,水分对胶稠度的影响不显著,肥水之间存在耦合效应;氮肥对直链淀粉含量影响大于水分处理,中肥节水灌溉使直链淀粉含量升高,高肥节水灌溉可降低辽优3225、沈农8801及沈农8714直链淀粉含量,节水灌溉使弯穗品种粳稻的蒸煮品质变劣;肥水处理对碱消值没有影响。     

油菜籽预处理工艺对粕残油率的影响

通过扫描电镜研究了油菜籽原料、高低粕残油率挤压膨化试样及传统螺旋压榨试样的显微组织结构.结果表明:粕残油率低的试样经挤压膨化后细胞壁破坏充分,物料膨化效果好,有利于溶剂油与油脂的迅速充分接触,从而提高油脂浸出速度、降低粕残油率(＜1%);相反,粕残油率高的试样细胞壁没有被充分破坏,传统压榨工艺试样组织结构坚实细密不利于油脂浸出,粕残油率相对较高(＞9%).