Physical and chemical properties of ultrasonically, spray-dried green banana (Musa cavendish) starch

Ultrasonic wave propagation and the spray dryer technique were applied to study their effect on the physical and chemical properties of green banana starch. The results showed high resistant starch content, which was reduced by ultrasound treatment and also by spray drying. Both techniques increased the solubility, swelling power and water absorption capacity. The gels exhibited non-Newtonian shear-thinning behavior, since flow behavior index was less than one (n < 1). Ultrasound wave propagation reduced yield stress and consistency coefficient in starch gels. Under oscillatory shear, all gels exhibited solid-like viscoelastic behavior, storage modulus was higher than loss modulus to entire frequency range (G′ > G′′), which was confirmed by the Cox-Merz experiment that showed that the complex dynamic viscosity was greater than the apparent viscosity in all samples. The gelatinization temperature was mainly influenced by drying technique and ultrasound treatment reduced the amount of energy required to gelatinize the starch.     

Characterization of gelatinized corn starch suspensions and resulting drop size distributions after effervescent atomization

Effervescent atomization is a promising method for economical atomization of high viscous liquids like gelatinized corn starch suspensions. The gelatinization of starch has strong influence on the viscosity of starch suspensions. It was characterized adapting a method for determination of the gelatinization degree. Rheological properties of gelatinized corn starch suspensions with concentrations ranging from 5 to 7 wt.-% were investigated. Effervescent atomization proved to be largely invariant to variations of liquid viscosity in this range. Relative gas injection pressure proved to be of highest influence on the resulting drop size distribution when varying only atomizer geometry. Applying Abel inversion to drop size measurement results depicted the opposite trend of drop sizes depending on radial position in the spray than observed by other researchers working with aqueous glass bead suspensions. Compared to conventional external mixing pneumatic atomization a reduction of atomization gas quantity of up to four times could be achieved.     

Suitability of pigeon pea and rice starches and their blends for noodle making

The physicochemical and pasting properties of pigeon pea and rice starches were studied to assess their suitability for noodle making. Amylose content, solubility and freeze thaw stability of pigeon pea starch were significantly higher than those of rice starch (p < 0.05). The pasting properties of peak viscosity, final viscosity, breakdown and set back showed higher values for pigeon pea starch, whereas hot paste viscosity and pasting temperature were higher for rice starch. Rice starch noodles revealed less cooking time (4 min) and less percent solids loss, whereas pigeon pea starch noodles had higher cooking time (12 min), higher percentage of water absorbed during cooking, more hardness and cohesiveness. Rice starch noodles scored higher for their transparency and slipperiness over pigeon pea starch noodles. Blending of pigeon pea starch with rice starch had significant effects on the cooking and sensory quality of noodles. Among starch blends, 70:30 blend of the pigeon pea and rice starches respectively resulted in good quality of noodles especially in terms of their higher transparency, slipperiness, overall acceptability and cohesiveness values. Blending of pigeon pea starch with 30% rice starch could produce noodles with superior quality as compared to native pigeon pea and rice starch noodles.     

酶解淀粉在纯棉纱低温上浆中的应用

探讨酶解淀粉在纯棉纱低温上浆中的应用效果。采用酶解淀粉在低温条件下煮浆和上浆,测试了浆液性能和对纯棉纱的浆纱性能,结果表明:酶解淀粉具有较低的黏度及黏度热稳定性,对纯棉纤维的黏附性较好,浆纱的强伸性能好,毛羽贴伏效果接近磷酸酯淀粉,耐磨性能略低于磷酸酯淀粉。     

Rapid small‐scale starch isolation using a combination of ultrasonic sonication and sucrose density separation

The proposed rapid small‐scale starch isolation technique in the laboratory was a combination of dry grinding of grain, suspension of the resulting flour in extraction buffer, application of ultrasonic sonication, then separation by sucrose density centrifugation. Light microscopy of separated fractions showed intact starch granules in the pellet and proteins and damaged starch in the top layer. The extraction method yielded 61% starch from sorghum and 63% from maize. The isolated starch showed lower starch damage and proteins content than by the conventional method. The gelatinization enthalpy of isolated starch was slightly higher than by wet grinding conventional method. In addition to low amount of starting flour (100 mg) the new starch isolation method was performed in less than 2 h from dry grinded seed to dried starch. Thus, it could be a useful method for cereal chemists and plant genetists.     

Isolation and partial characterization of Mexican taro (Colocasia esculenta L.) starch

Taro starch was isolated from Mexican variety and its morphological, physicochemical, and molecular characteristics were evaluated. Yield starch (in dry basis) was 81%, and this starch had low AM content (2.5%). Taro starch granules showed a mixture of shapes with sizes between 1 and 5 µm. Taro starch presented an A‐type XRD pattern with a crystallinity level of 38.26%. Solubility and water retention capacity did not change in the temperature range of 50–70°C and thereafter they increased as temperature increased too. Taro starch showed high peak viscosity due to its high AP content. The peak temperature of gelatinization of taro starch was 80.6°C with an enthalpy value of 10.6 J/g, with low retrogradation rate due to its low AM content. Weight‐average molar mass (Mw) and gyration radius (Rz) of taro starch were 1.21 ± 0.8 × 10⁹ g/mol and 424 ± 70 nm, respectively. Taro tuber could be an alternative for starch isolation with functional and physicochemical characteristics for food and non‐food applications.     

Preparation and Properties of Physically Modified Banana Starch Prepared by Alcoholic‐Alkaline Treatment

Granular cold‐water‐soluble (GCWS) starches were prepared from banana starch treating it with 40 and 60% aqueous ethanol at two controlled temperatures (25 and 35 °C). GCWS starches prepared at 25 °C and with 40 and 60% aqueous ethanol had the lowest cold‐water solubility, that prepared with 40% aqueous ethanol at 35 °C and stored at room temperature showed low tendency to retrogradation, as assessed by transmittance. Solubility and swelling profiles were similar for GCWS starches and the freeze‐thaw stability of GCWS starches was increased as compared with native starch. The apparent viscosity of GCWS banana starches was higher than that of its native starch counterpart.     

Effects of Modification Sequence on Structures and Properties of Hydroxypropylated and Crosslinked Waxy Maize Starch

The effects of modification sequence on chemical structures and physicochemical properties of hydroxypropylated (HP) and crosslinked (XL) waxy maize starch were investigated. The physicochemical properties, including pasting, gelling, and thermal properties, were studied. The chemical structures of dual‐modified starches and their beta‐limit dextrins were characterized with high‐performance liquid chromatography. The HP‐XL starch had higher Brabender viscosity than did the XL‐HP starch at both pH 7 and 3; however, both showed similar gelling properties. Significantly higher onset and peak gelatinization temperatures, gelatinization enthalpy, and lower retrogradation were observed for the HP‐XL starch. The HP‐XL starch also exhibited significantly higher beta‐amylolysis limit and higher content of low molecular weight saccharides in its isoamylase‐debranched starch, suggesting its structure was more accessible to enzymatic attack than the XL‐HP starch. Structural analyses revealed different distribution patterns of modifying groups between the two modified starches. The results indicate that the modification sequence altered the susceptibility to enzymes, changed the locations of substitution, and modified the physicochemical properties of the HP and XL waxy maize starches.     

石油工业中淀粉产品的开发和利用

许多淀粉产品用于石油工业，如黄原胶、羧甲基淀粉、预糊化淀粉和接枝淀粉等。本文介绍了这些产品的主要生产工艺和性能，以及在石油钻井、石油采集和油田污水处理等方面的应用。     

可食性宠物淀粉玩具的研究

以淀粉、明胶和牛皮下脚料为主要原料，通过添加增塑荆、交联荆、填充荆、脱模荆等物质，经注射成型制备狗骨头（宠物玩具），研究了最佳配方及工艺参数。