大批量小样品豆腐与豆乳得率的定量分析技术研究

STUDY ON MEASUREMENT TECHNOLOGY OF TOFU AND SOYMILK OUTPUT FOR LARGE AMOUNT OF MINI-SPECIMEN

豆腐与豆乳的育种和资源研究需要对大批量小样品进行得率的测定,为选择提供快速而又相对精确的依据。本研究目的是在前人基础上改进小样品豆腐与豆乳得率的实验室定量分析技术,进而提出精确、稳定、规范的测定流程。主要研究内容为以干磨代替湿磨,选用性能稳定可控性好的FOSS Tecator 1095样品磨,干磨豆粉;以6个百粒重差异较大的大豆品种为供试材料,分析不同磨豆时间、不同滤渣条件对小样品豆腐与豆乳得率的影响。结果表明,磨粉时间50 s,循环水式多用真空泵经120目滤网减压室温抽滤1 min的豆腐与豆乳得率最高,误差最低。提出以下流程作为规范化豆腐与豆乳得率实验室定量分析技术:精确称取经FOSS样品磨50 s磨碎的豆粉5.00 g,以150 mL自来水室温浸泡2 h,采用循环水式多用真空泵经120目滤网减压(真空度0.098 Mpa)室温抽滤1 min,分取20 mL浆液烘干测干豆乳得率;另取20 mL浆液置于95℃水浴约15 min(浆面温度呈90℃)、冷却至约80℃加0.6 mLCaSO4过饱和溶液点浆,搅拌,蹲脑30 min,经16,000 r/min离心10 min,倾去上清液得湿豆腐,120℃烘干24 h测干豆腐得率。经大量实验验证,改进后的方法具有快速、精确、高效的优点。

A rapid mini-specimen technology is the key for germplasm study and genetic improvement of tofu and soymilk output.The objective of the present study was to establish a mini-specimen measurement technology for standardization of tofu and soymilk output in laboratory based on the previous methods.By using FOSS Tecator 1095 Sample Mill with grinding speed of 20,000 r/min,the effects of grinding time,filter sieve size and filtering method for tofu and soymilk output were studied on six diverse 100-seed-weight soybean varieties.The procedure with a grinding time 50 s and filtering through 120 or 100 mesh nylon sieve under 0.098 Mpa with a cycling water vacuum pump for 1 min provided the highest output and lowest error for measurement of dried tofu and soymilk output.A mini-specimen technology for tofu and soymilk output was developed as the following: a specimen of 5.00 g soybean powder ground from dried seed with FOSS Tecator 1095 Sample Mill at 20 000 r/min for 50 s,blended with 150 mL tap water at room temperature for about 2 h to produce a slurry,then filtered through a 120 mesh nylon sieve under 0.098 Mpa with a cycling water vacuum pump to obtain soymilk.To prepare tofu,four tubes of soymilk specimen(20 mL per tube) are heated in water bath at 95 ℃ for 15 min,cooled down to 80℃,then added with supersaturated aqueous solution of CaSO4(0.6 mL per tube) and stirred,coagulating for 30 min,then centrifuged at 16 000 r/min(4 ℃) for 10 min to obtain wet tofu.Soymilk and wet tofu are dried in oven at 120 ℃ for 24 h till consistent weight to get dried soymilk and dried tofu.