Young Consumers Evaluate A Study On The Taste Quality Of Rice

Sensory evaluation techniques have been gradually applied to the variety screening and quality improvement of agricultural products in recent years.In this research,12 varieties of rice were studied.Firstly,the lexicon understandable by young consumers for raw rice and cooked rice were respectively established by using Flash Profile method.Secondly,combined with Rate-All-That-Apply and consumer preference evaluation,sensory attributes affecting young consumer preference were investigated on both raw rice and cooked rice.Meanwhile,the physical and chemical characteristics of different samples were measured to explore the correlation between physical and chemical characteristics and sensory attributes.The results were shown as following.(1)Six rice samples were evaluated by Flash Profile method.After the descriptors were developed and combined,6 first-level and 16 second-level attributes for raw rice and 5 first-level and 17 second-level attributes for cooked rice were generated,respectively.The 15-cm linear scale and ranking test showed that consumers could distinguish different varieties of rice.Moreover,the characteristics of each sample could be analyzed by sample factor and sensory characteristic loading plots.For example,Super S was full and shiny,and SH19 rice was prominent in rice aroma,while TWT and SH19 rice were similar in shape with large and slender rice grains.(2)Twelve kinds of rice were tested simultaneously by 9-point hedonic test,RATA test and related physical and chemical properties(such as length,thickness,width,broken rice rate,chalkiness rate,color,texture,protein content and amylose content).The results showed that there were significant differences in overall liking of appearance,likings of color,shape,size,gloss,transparency,plumpness,smoothness and odor among 12 varieties of raw rice(P<0.05).Among them,Super S,BYYX,HX and DX had higher scores of overall liking of appearance and various appearance characteristics favored by consumers.Liking of color contributed the most to overall liking of appearance,followed by liking of shape.SH68 and NX9108 were least liked among young consumers.However,the aromas of all varieties of raw rice were insufficient and suggested to be strengthened.Among the 12 varieties of cooked rice,HX had the highest overall liking score,mostly contributed by the liking of texture.TWT was least favored by young consumers because of its low humidity,poor gloss,low transparency and poor fineness.In addition,the elasticity,chewiness and aroma of various cooked rice were insufficient and would be appropriately strengthened.(3)The volatile compounds in 10 varieties of both raw rice and cooked rice were detected by SPME-GC-MS and GC-IMS,respectively.Through SPME-GC-MS,142 volatile compounds were detected in 10 varieties of raw rice,in which most were hydrocarbons,alcohols,aldehydes,esters and ketones.49 volatiles,mostly including aldehydes,alkanes,hydrocarbons,and alcohols,were detected in 10 cooked rice.The aldehydes and alcohols detected in SH19 with a longer storage time were higher than those in fresh rice.Through hierarchical cluster analysis,rice varieties would be well classified at 19 and 15 horizontal distances,in which primary classification analysis could be carried out on between fragrant rice and non-fragrant rice,as well as on between aged rice and non-aged rice.Through GC-IMS,93 and 55 volatile compounds were detected in raw rice and cooked rice,respectively.Esters,alcohols,ketones and aldehydes were the majority in raw rice,while alcohols,aldehydes and esters for cooked rice.There were differences in the composition of volatile flavor compounds among different varieties.Through principal component analysis,the different volatile compositions could better distinguish 10 varieties of raw rice.Except for rice varieties of SH19 and HX,8 varieties had little difference in volatile substances compositions after cooked.Compared with raw rice,cooked rice was more concentrated in plot,and thus their flavor difference were smaller.The application of modern sensory evaluation techniques on evaluation of rice quality could potentially develop new evaluation standards on rice products,thus offering sufficient information for breeding study,which would possibly help the researchers to cultivate new rice varieties with good quality,high nutrition,good taste and good comprehensive properties to better meet the requirements and expectations of the consumers.