Search Results (5)

Food quality and safety are paramount in preserving the culinary authenticity and cultural integrity of Chinese cuisine, characterized by intricate ingredient combinations, diverse cooking techniques (e.g., stir-frying, steaming, and braising), and region-specific flavor profiles. Traditional non-destructive detection methods often struggle with the unique challenges posed by Chinese dishes, including complex textural variations in staple foods (e.g., noodles, dumplings), layered seasoning compositions (e.g., soy sauce, Sichuan peppercorns), and oil-rich cooking media. This study pioneers a hyperspectral imaging framework enhanced with domain-specific deep learning algorithms (spatial–spectral convolutional networks with attention mechanisms) to address these challenges. Our approach effectively deciphers the subtle spectral fingerprints of Chinese-specific ingredients (e.g., fermented black beans, lotus root) and quantifies critical quality indicators, achieving an average classification accuracy of 97.8% across 15 major Chinese dish categories. Specifically, the model demonstrates high precision in quantifying chili oil content in Mapo Tofu with a Mean Absolute Error (MAE) of 0.43% w/w and assessing freshness gradients in Cantonese dim sum (Shrimp Har Gow) with a classification accuracy of 95.2% for three distinct freshness levels. This approach leverages the detailed spectral information provided by hyperspectral imaging to automate the classification and detection of Chinese dishes, significantly improving both the accuracy of image-based food classification by >15 percentage points compared to traditional RGB methods and enhancing food quality safety assessment. Full article

Static magnetic field (SMF) treatment is a new type of physical preservation method. In this study, SMF treatment was applied to fresh-cut lotus root to investigate its effects and possible mechanisms in terms of preserving color and maintaining freshness, with the goal of developing a preservation method for fresh-cut lotus root. Fresh-cut lotus root was treated with a magnetic field strength of 3 mt and stored for 14 days under cold conditions (temperature 4 °C, humidity 70%, wind speed 0.1–0.3 m/s, and no light). The control group received no SMF treatments. The effects of the SMF on the color, hardness, browning, weight loss, soluble solids content, vitamin C (Vit. C) content, and polyphenol content, as well as the activities of MDA, POD, PPO, and PAL and the contents of flavor substances of the fresh-cut lotus root were monitored every 2 days throughout the storage period. The results showed that the SMF treatment significantly slowed the decline in the sensory quality of fresh-cut lotus root (p < 0.05). After 6 days of storage, the degree of browning in the control group was 1.96 times that in the SMF group. The SMF treatment also significantly delayed reductions in the Vit. C and polyphenol contents in fresh-cut lotus root (p < 0.05). After 8 days of storage, the polyphenol content in the SMF group was 1.54 times that in the control group. After 12 days of storage, the Vit. C content of the SMF group was 1.45 times that of the control group. When the storage time reached 12 days, the L* and ΔE values of the control group were 1.89 times and 1.44 times those of the SMF group, respectively. The SMF treatment significantly reduced the activities of PPO and POD oxidases, as well as the MDA content (p < 0.05). After 12 days of storage, the activities of PPO and POD and the MDA content in the control group were 2.04 times, 1.42 times, and 1.71 times higher than those in the SMF group, respectively. After 14 days of storage, the weight loss rate in the control group was 1.65 times that in the SMF group, while the hardness of the SMF group was 1.23 times that of the control group. The SMF treatment increased the contents of esters, aldehydes, and ketones in fresh-cut lotus root compared with the control group. The contents of esters, aldehydes, and ketones in the SMF group were 1.04 times, 1.41 times, and 1.49 times higher than those in the control group, respectively. Moreover, using SMF treatment as a new preservation method for fresh-cut lotus root provides a promising strategy for preserving other fresh-cut fruits and vegetables. Full article

Fragrant rice has various flavor types, mainly the popcorn flavor, corn flavor and lotus root flavor. Chinese fragrant rice from China and Thai fragrant rice from Thailand were analyzed. GC-MS was used to determine the volatile compounds of fragrant rice. It was found that there were 28 identical volatile compounds between Chinese and Thai fragrant rice. The key compounds of different flavor types of fragrant rice were obtained by comparing the common volatile compounds. The key compounds of the popcorn flavor were 2-butyl-2-octenal, 4-methylbenzaldehyde, ethyl 4-(ethyloxy)-2-oxobut-3-enoate and methoxy-phenyl-oxime. The key compounds of the corn flavor were 2,2′,5,5′-tetramethyl-1,1′-biphenyl, 1-hexadecanol, 5-ethylcyclopent-1-enecarboxaldehyde and cis-muurola-4(14), 5-diene. By using a combination of GC-MS and GC-O, the flavor spectrogram of fragrant rice was constructed, and the characteristic flavor compounds of each flavor type were identified. It was found that the characteristic flavor compounds of the popcorn flavor were 2-butyl-2-octenal, 2-pentadecanone, 2-acetyl-1-pyrroline, 4-methylbenzaldehyde, 6,10,14-trimethyl-2-pentadecanone, phenol and methoxy-phenyl-oxime. The characteristic flavor compounds of the corn flavor were 1-octen-3-ol, 2-acetyl-1-pyrroline, 3-methylbutyl 2-ethylhexanoate, methylcarbamate, phenol, nonanal and cis-muurola-4(14), 5-diene. The characteristic flavor compounds of the lotus root flavor were 2-acetyl-1-pyrroline, 10-undecenal, 1-nonanol, 1-undecanol, phytol and 6,10,14-trimethyl-2-pentadecanone. The resistant starch content of lotus root flavor rice was relatively high (0.8%). The correlation between flavor volatiles and functional components was analyzed. It was found that the fat acidity of fragrant rice was highly correlated (R = 0.86) with the characteristic flavor compounds, such as 1-octen-3-ol, 2-butyl-2-octenal and 3-methylbutyl-2-ethylhexanoate. The characteristic flavor compounds had an interactive contribution to the production of the different flavor types of fragrant rice. Full article

The changes in the texture and flavor of lotus root were determined before and after boiling, steaming and frying. Compared to fresh lotus root, all three kinds of cooking decreased the hardness and springiness, and frying significantly enhanced the gumminess, chewiness and cohesiveness. The flavor components, such as flavor amino acids, nucleotides and their taste character in lotus roots, were determined by liquid chromatography and electronic tongue. The amino acids and nucleotide contents of fresh lotus root were 20.9 and 0.07 μg/kg, respectively. The content of flavor substances in lotus roots decreased obviously, and the texture characteristics decreased after boiling and steaming. After deep-frying for 2 min, the free amino acids and nucleotide contents of lotus root were 32.09 and 0.85 μg/kg, respectively, which were the highest in all cooking methods. The contents of volatile flavor components and their smell character in lotus roots were determined by GC-MS and electronic nose. There were 58 kinds of flavor compounds identified in fresh lotus root, mainly alcohols, esters and olefins. The total amount of volatile flavor compounds decreased, and new compounds, such as benzene derivatives, were produced in lotus roots after boiling and steaming. After deep-frying, the content of volatile flavor compounds in lotus root increased significantly, especially the aldehyde volatile flavor compounds. The production of pyran, pyrazine and pyridine volatile flavor compounds made the lotus root flavor unique and delicious. The taste and smell character of lotus roots before and after cooking were effectively separated by an electronic tongue, nose and PCA analysis; the results suggested the boiled lotus root exhibited the most natural and characteristic taste and smell among the four groups. Full article

Marinated vegetables are traditional cold dishes with a long history and special flavor in the Chinese deli market. However, the traditional thermal-and-soaking (TS) procedure often results in unreproducible flavor quality properties of marinated vegetables and waste of brine and time in production. A novel green and sustainable technique, high-pressure processing (HPP), has caught the attention of the food industry. In this study, the effects of HPP and TS treatment on the visual, flavor, textural, and microbiological qualities of Chinese marinated lotus root slices were investigated. Compared to the TS products, lighter color, more varieties of volatile compounds, and crunchier texture were detected in the HPP products. Throughout the 4 °C, 25 °C, and 45 °C shelf life challenges, the HPP products retained their original color and crunchiness better than the TS ones, whereas no significant differences were found in total viable counts (TVCs) in the first half of the shelf lives. The Arrhenius model under the first-order reaction of TVC deterioration showed a good fit to the shelf life of the HPP marinated lotus root slices. This study demonstrates that HPP may assist in making the best use of brine in a more time-efficient manner to improve the visual, flavor, and textural quality of traditional Chinese marinated lotus root slices. Full article