Effect of Pre-Gelatinization Conditions on the Total Oxalate Content and Techno-Functional Properties of Taro (Colocasia esculenta) Flour

Like most roots and tubers, taro (Colocasia esculenta) corms have a short shelf-life due to the high moisture content, which aggravates their post-harvest losses. They also contain high amounts of calcium oxalates, limiting their use in food applications. To help add value and diversify the use of taro corms as well as curb food losses, various strategies have been proposed, such processing of the corms into flour. This study aimed at evaluating the total oxalate content and techno-functional properties of taro flour as affected by the pre-gelatinization conditions (i.e., method and time). Pre-gelatinized taro flour was prepared by subjecting peeled and cleaned taro corms to roasting (190°C), boiling (100°C), and steaming (100°C) for 10 min, 20 min and 30 min, respectively, for each method, followed by drying at 55°C and milling. Generally, all the properties of flour were significantly affected by the pre-gelatinization conditions (P 0.05). The total oxalate content of the pre-gelatinized taro flour ranged from 33.26 to 76.90 mg/100g. Pre-gelatinization by boiling significantly reduced the oxalate content (56.7%), while roasting resulted in the least reduction (36.2%). The flour colour i.e. L*, hue, and chroma ranged from 38.47° - 70.30°, 42.64° - 69.43°, and 7.78° - 10.58°, respectively. Roasting resulted in flour with the largest L* (70.30°) and hue angle (69.43°). Boiling also resulted in flour with the highest bulk density (BD) (0.86 g/cm3) and the lowest water solubility index (WSI) (9.39%). Steamed flour had the highest water absorption index (WAI) (3.81 g/g), water holding capacity (WHC) (4.59 g/g), and swelling capacity (SC) (4.86 g/g). This study shows that pre-gelatinization (i.e. by boiling, steaming or roasting) significantly affects the total oxalate content and techno-functional properties of taro flour, which in turn influences its use in other food applications thus increasing the utilization and production of taro simultaneously.

加工因素对张溪香芋全粉品质影响

以张溪香芋为原料,采用析因实验设计,研究了加工因素,如切片厚度、蒸煮时间及其交互作用,对香芋全粉品质的影响,优化香芋全粉的加工工艺。实验中对不同切片厚度和蒸煮时间制备的香芋全粉的碘蓝值、糊化度、吸水性、吸油性进行品质评价,为香芋全粉的工厂实践提供理论依据。结果表明:切片厚度和蒸煮时间对香芋全粉的品质存在显著性(ρ<0.05)影响。香芋全粉在切片厚度为3 mm、蒸煮时间为15 min时,全粉的碘蓝值3.18、吸水性6.20、吸油性1.02,各个样品的糊化度均在90%以上。将其应用到婴幼儿奶粉、老人的营养早餐中,有利于消化、吸收,具有很大的开发应用前景。

芋头小米面条加工参数的优化

利用正交试验和方差分析,对芋头小米面条的工艺参数优化。试验结果表明,芋头粉、小米的添加量对面条品质的影响很大,添加量均为5%时,混合粉的糊化特性较好,峰值黏度为112.22 RVU,谷值黏度为82.06 RVU,硬度均在120 g^135 g之间,面条的感官品质较好,面条的蒸煮损失率均在4%以下。正交试验及方差分析确定,芋头粉和小米粉的添加量均为5%,加水量为39%;和面时间为12 min,在此条件下制成的面条,感官性状和蒸煮品质均呈现良好状态。

螺旋藻芋头豆粉团团的工艺优化

选取优质的黑豆粉、螺旋藻、莱阳孤芋、菠菜为主要原料,通过黑豆粉和螺旋藻、菠菜的合理搭配,加入芋泥,改进以糯米粉为主要原料的传统做法;通过单因素实验与响应面实验探索螺旋藻芋头豆粉团团的最佳生产工艺。结果表明:黑豆粉添加量为9%,螺旋藻添加量为0.10%,白砂糖添加量为7%,蒸制时间为14min时,获得的产品色泽天然,呈浅绿色,细腻软糯,甜度适宜,具有浓郁的豆香味。

亲水胶体对红芽芋全粉理化特性和消化特性的影响

分别将κ-卡拉胶、黄原胶和瓜尔胶3种亲水胶体以不同比例(0.4%、0.8%)与红芽芋全粉进行复配,研究两者复配后理化特性和消化特性的变化。结果表明,添加3种胶体后,复配体系的持水性、膨胀度和RVA值均有不同程度的提升,其持油性和回生值有所下降。κ-卡拉胶和瓜尔胶可降低体系析水率,提高冻融稳定性,而黄原胶只有在第3次冻融处理下能提高冻融稳定性。与空白组相比,3种胶体复配体系的硬度和咀嚼性下降,黏度上升。在消化特性结果中,添加3种胶体均可使易消化淀粉(RDS)含量降低,抗性淀粉(RS)含量升高,其中加入0.8%黄原胶能使RS质量分数从10.11%升至19.85%。

不同干燥条件对张溪香芋全粉品质的影响

以张溪香芋为原料,经去皮切片蒸煮,采用日晒(约35℃)、不同温度(60℃、70℃和100℃)热风干燥四种不同干燥条件进行干燥,以干燥后粉碎所得的香芋全粉的色泽、水分、吸水性、吸油性、含糖量、蛋白质含量和颗粒分散性为指标,研究了不同干燥条件对张溪香芋全粉品质的影响。结果表明采用60℃低温热风干燥得到的张溪香芋全粉综合品质最佳,全粉色泽较浅偏白色,颗粒粒径均匀,分散性好,营养成分含量较高,具有较好的吸水性和吸油性。

香芋面条的制备及其品质影响研究

以香芋粉为原料,按不同比例与小麦粉进行混合处理,研究香芋粉添加量对混合粉蛋白质品质及面团拉伸特性的影响。在较优配比的混合粉中添加品质改良剂后制作面条,以感官评分、蒸煮特性为指标,在单因素实验的基础上运用正交实验优化工艺条件。结果表明,最佳工艺条件为香芋粉与小麦粉的比例为6:4、谷朊粉添加量为4%、黄原胶添加量为0.25%、羧甲基纤维素钠的添加量为0.15%、海藻酸钠的添加量为0.45%,此条件下香芋面条几乎不断条,感官评分为92.5分,蒸煮损失率为3.82%,面条拉伸特性为拉伸面积256.14 g·mm、拉断力50.61 g、拉伸距离13.57 mm。