Background and Objectives The eating quality of fresh instant rice differ significantly owing to its geographical origins. However, the method of geographical discrimination is still lacking. In this study, the determination of flavor profiles and multivariate statistical analysis have been applied for discriminating the geographical origins of 18 fresh instant rice from three provinces in Northeast China. Findings The principal component analysis (PCA) of electronic nose (E‐nose) data could rapidly distinguish the samples from three different provinces. The solid phase microextraction‐gas chromatograph‐mass spectrometer (SPME‐GC‐MS) results of samples from different provinces were clearly distinguished in PCA and hierarchical cluster analysis (HCA). The orthogonal partial least squares discriminant analysis (OPLS‐DA) model showed good discriminating ability (R2 = 0.894, Q2 = 0.845, and accuracy = 1.0). Nonanal, 2,4‐di‐tert‐butylphenol, 2,3‐dihydro‐benzofuran, 2‐pentylfuran, indole, pentadecane, 2‐pentadecanone, trans‐farnesol, isopropyl palmitate, and farnesyl acetone were identified as 10 marker compounds. Moreover, their good discrimination was verified in an additional nine samples. Conclusions The strategy of applying flavor profiles for discriminating the geographical origin of fresh instant rice has been proven to be an efficient and non‐destructive method. Significance and Novelty Our study is helpful to control the quality of fresh instant rice and provides a methodological reference for the geographical discrimination of foods.

Rice’s geographic origin and variety play a vital role in commercial rice trade and consumption. However, a method for rapidly discriminating the geographical origins of rice from a different region is still lacking. Therefore, the current study developed a volatile organic compound (VOC) based geographical discrimination method using headspace gas chromatography-mass spectrometry (HS-GC-MS) to discriminate rice samples from Heilongjiang, Jilin, and Liaoning provinces. The rice VOCs in Heilongjiang, Liaoning, and Jilin were analyzed by agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the optimum parameters for headspace solid phase microextraction (HS-SPME) involved the extraction of 3.0 g of rice at 80 °C within 40 min. A total of 35 VOCs were identified from 30 rice varieties from Northeast China. The PLS-DA model exhibited good discrimination (R2 = 0.992, Q2 = 0.983, and Accuracy = 1.0) for rice samples from Heilongjiang, Liaoning, and Jilin. Moreover, K-nearest neighbors showed good specificity (100%) and accuracy (100%) in identifying the origin of samples. In conclusion, the present study established VOC fingerprinting as a highly efficient approach to identifying rice’s geographical origin. Our findings highlight the ability to discriminate rice from Heilongjiang, Liaoning, and Jilin provinces rapidly.

Background and objectives Eating quality is an important quality index of rice, which also determines production and sales. However, previous rice breeding mainly took yield as the gold index, and almost no comprehensive consideration of its eating quality. In this study, to further select new high‐quality japonica rice variety, the eating quality differences in the physicochemical, texture, pasting properties, and volatile compounds between five newly bred varieties (JR5, JR6, JR8, JR9, and JR10) and one commercial variety (Kenyu38) were analyzed. Findings Correlation analysis results indicated that the taste value was negatively correlated with protein (r = −.953, p < .01), amylose content (r = −.915, p < .05), and setback value (r = −.902, p < .05). JR5 had a better appearance and taste quality with significantly lower protein content, amylose content, pasting temperature, and setback value. Moreover, the electronic nose could clearly distinguish JR5 from other rice samples. Aroma analysis showed that JR5 had the significantly higher content of 1‐octene‐3‐ol and hexanal, which were important odor‐active volatile compound in cooked rice. Conclusions JR5 had better eating quality than Kenyu38 and could be used as an excellent variety for further popularization. Significance and novelty This study provides a new perspective for the selection of high‐quality rice varieties.

Rice's yield, cooking, and sensory quality are primary considerations in selecting new breeding rice varieties, which are determined by the rice eating quality such as processing and flavor characteristics. Thus, in this study, to advance the breed of new superior japonica rice varieties, the differences in the rice quality, processing characteristics, and flavor characteristics between 12 newly-bred varieties (

By simulating the aroma changes during in vitro mastication, we can better understand the aroma changes during rice eating, which is helpful in studying people’s sensory preferences. To investigate the rice aroma released during the in vitro mastication, the present study analyzed rice bolus’s odor fingerprints in vitro mastication using electronic nose and gas chromatography-ion mobility spectrometry (GC-IMS). The electronic nose analysis results showed significant differences in the flavor of japonica rice in vitro mastication. In addition, GC-IMS determined 30 volatile organic compounds (VOCs) during rice in vitro mastication. Among these compounds, the most important content was aldehydes, followed by ketones and alcohols. Although the concentration of various chemicals was relatively high in cooked rice, most compounds decreased after mastication. The concentration of propan-2-ol, ethanol, and methanol increased after mastication. Multivariate data analysis showed that isoamyl sovalerate, pentanal, hexanal, acetone, hexanal, and limonene were the main VOCs of japonica rice during in vitro mastication. GC-IMS and e-nose analyses are complementary and recommended for using the two techniques to achieve the VOCs’ rapid and comprehensive detection during in vitro mastication. Results from this study allowed us to understand rice flavor during oral processing.