Study On The Methods Of Sensory Evaluation For Lanzhou Alkaline Hand-extended Noodles

A Chinese Standard Methods(SB/T 10137-1993)(established by Ministry of Commerce of China) or with some modification, has been commonly used to evaluate the quality of Lanzhou alkaline hand-extended noodles. Some scholars pointed out that the sensory parameters weightings were unreasonable and the influence of handmade procedure on scoring systems was largely ignored due to lack of recognition of the importance of processing.To establish an accurate, objective and reasonable scoring system to evaluate the quality of Lanzhou alka line hand-extended noodles, quality attributes and scores for hand-extended noodles sensory evaluation were selected from research papers. Eight commercial wheat flours with big quality difference were used to make the noodles followed with a sensory evaluation by cook masters and panelists. The scoring methods for process procedure and cooked noodles are calculated by weighted sum method to identify the differences of quality attributes in different wheat flours. Two commercial flours with biggest difference in quality selected from the former experiment were mixed into different proportions and evaluated with the same method. Statistical analysis was carried out to study the relations hip between the quality attributes of process procedure and the quality attributes of cooked noodles. Finally, quality attributes weightings in process procedure and cooked noodles were adjusted by the relationship obtained and the consumer acceptability survey(by cook masters and consumer). Scoring systems for the process procedure and cooked noodles were established ultimately. By analyzing the extent effect of commercial alkaline agents, inorganic salts, hydrocolloids on rheological properties of wheat flour, the optimal addition was determined.The main results were as follow s:(1) ‘Ease of mixing and degree of dough firmness’, ‘fracture of strips and its homogeneity’, ‘slitting effort by hand and dough stickiness’, ‘dough color after resting’, and ‘stretching force’ were developed to assess the quality attributes of processing procedure of Lanzhou hand-extended noodles. Scor es were assigned to the various attributes as 35, 20, 15, 15, 15, respectively.(2) Seven qua lity attributes inc lud ing ‘elasticity’, ‘softness’, ‘color’, ‘surface appearance’, ‘smoothness’, ‘stickiness’, ‘flavor ’ were selected to assess the quality attr ibutes of cooked Lanzhou hand extended noodles. The weights of each quality attributes were adjusted by the consumer acceptance survey and were assigned to be 30, 20, 20, 10, 10, 5, 5, respectively.(3) The rheological properties of wheat flour were significantly improved by the commercial alka line agents. In addition, commercial agents have different effects on rheological properties of wheat flour dough due to the different flour qua lity. Medium-strong gluten wheat flour with maximum 0.8% commercial agents addition and while 0.4% for medium gluten wheat flour were suggested.(4) The rheological properties of wheat dough were significantly improved when the salt, sodium carbonate, sodium dehydrogen phosphate, sodium alginate, xanthan gum, carrageenan addition were 0.5%-2.0%, 0.15%-0.20%, 0. 2%-0.5%, 0.20%-0.25%, 0. 1%, 0. 1%, respectively.This research is a case study on the Chinese traditional food by using scientific and applicable establishment of sensory test, which established sensory evaluation methods for Lanzhou alkaline hand-extended noodles including processing procedure and cooked noodles, providing the scoring method for noodles flour standards, noodle quality evaluation, skills assessment for cook masters and breeding of wheat with particular varieties.