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BACKGROUND: Roasting is an important process in the formation of coffee flavor characteristics, which determines the quality of coffee and consumer acceptance. However, the influence of roasting degree on the flavor characteristics of cold brew coffee has not been fully described. RESULTS: In the present study, the flavor characteristics of cold brew coffee with different roasting degrees were compared in detail by using chromatographic and electronic sensory approaches, and the flavor changes induced by freeze‐drying were investigated. Pyrazine and heterocyclic compounds were the main aroma compounds in coffee, and gradually dominated with the increase of roasting. Pyridine was consistently present in cold brew coffees of different roasting degrees and showed significant gradient of quantity accumulation. Aroma compounds such as pyrazine, linalool and furfuryl acetate were the main contributors to coffee roasting, floral and fruity flavor. Freeze‐drying preserved the fruity and floral aromas of medium‐roasted cold brew coffee, whereas reducing the bitterness, astringency and acidity properties that are off‐putting to consumers. CONCLUSION: The higher consumer acceptance and enjoyment in medium roast cold brew coffee may be related to its stronger floral and fruity aroma. The aroma profile qualities of freeze‐drying processed medium roasted cold brewed coffee were more dominant and more suitable for freeze‐drying processing than medium dark roasting. Application of freeze‐drying for cold brew coffee will promote the convenience of drinking. The present study provides valuable technical guidance in improving the flavor and quality of cold brew coffee, and also promotes its commercialization process. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Waxy maize (Zea mays L. sinensis Kulesh) is a good material for brewing. Waxy maize wine, a kind of Chinese rice wine, is strongly affected by a fermentation starter named Qu. In this study, an innovative mixed Qu, consisting of two yeasts and three molds, was produced and the raw‐starch brewing method was applied in winemaking. Three other waxy maize wines fermented by three kinds of commercial Qu were also analyzed for comparison. RESULTS: Due to superb growth and fermentation characteristics, Saccharomyces cerevisiae CICC1009 and Pichia anomala CICC1851 were chosen to produce yeast Qu. The addition amount of yeast Qu was determined to be 30 g kg−1. In terms of chemical properties, mixed Qu was more suitable for making maize wine by the raw‐starch brewing method than the three kinds of commercial Qu with which it was compared. The most influential components for the overall aroma profile in maize wines fermented by mixed Qu and Mifeng Qu were ethyl butyrate and β‐damascenone, respectively, while in maize wines fermented by Angel Qu and Like Qu the most influential component was ethyl octanoate. Obvious differences were found among four maize wines regarding bitterness, umami, richness, saltiness, and sourness by the electronic tongue. The olfactory characteristics of maize wine fermented by Mifeng Qu were quite different from the other three according to the electronic nose. CONCLUSION: The innovative mixed Qu can be considered as an excellent starter for raw‐starch brewing of waxy maize. The chemical indices and volatile flavor compounds of waxy maize wines were greatly affected by different kinds of Qu. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Because of its high nutritional value and good sensory properties, fragrant rice is very popular all over the world. The aroma and taste of fragrant rice play an essential role in its sensory properties. However, there has been a lack of studies on flavor changes in fragrant rice during storage. RESULTS: Hexanal, nonanal, benzaldehyde, hexadecanoic acid, and methyl ester, were identified as aroma‐active compounds in fresh fragrant rice. After storage, more than 100 volatile compounds can be identified. The results indicated that, at high‐temperature storage, volatile compounds such as aldehydes, ketones, and furans increased, which led to a deterioration in rice quality. Marker compounds of flavor deterioration, methyl palmitate, 2‐methyl‐propanoic acid, and 3‐hydroxy‐2,2,4‐trimethylpentyl ester, were determined by principal component analysis. In addition to threonine and proline, the other 14 amino acids contributed to the taste of fragrant rice during storage. Sucrose is the only main contributor to the sweetness of Daohuaxiang 2, whereas glucose and fructose had a little sweet taste contribution during storage. The electronic nose (e‐nose) and the electronic tongue (e‐tongue) could distinguish samples with different storage conditions. CONCLUSION: Different storage conditions can cause flavor differences in fragrant rice. Especially under high‐temperature storage, volatile compounds such as aldehydes, ketones, and furans increase, which is an important reason for the deterioration in the quality of fragrant rice during storage. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The quality of virgin olive oil is related to the agronomic conditions of the olive fruits and the process variables of the production process. Nowadays, food markets demand better products in terms of safety, health and organoleptic properties with competitive prices. Innovative techniques for process control, inspection and classification have been developed in order to to achieve these requirements. This paper presents a review of the most significant sensing technologies which are increasingly used in the olive oil industry to supervise and control the virgin olive oil production process. Throughout the present work, the main research studies in the literature that employ non-invasive technologies such as infrared spectroscopy, computer vision, machine olfaction technology, electronic tongues and dielectric spectroscopy are analysed and their main results and conclusions are presented. These technologies are used on olive fruit, olive slurry and olive oil to determine parameters such as acidity, peroxide indexes, ripening indexes, organoleptic properties and minor components, among others. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND The aim of this study is to investigate the feasibility of a 'holistic' approach, using near infrared ( NIR) spectroscopy and electronic devices (electronic nose and electronic tongue), as instrumental tools for the classification of different coffee varieties. Analyses were performed on green coffee, on ground roasted coffee and on coffee beverage. Principal component analysis was applied on spectral and sensory data to uncover correlations between samples and variables. After variable selection, linear discriminant analysis was used to classify the samples on the basis of the three coffee classes: Robusta, natural Arabica and washed Arabica. RESULTS Linear discriminant analysis demonstrates the practicability of this approach: the external test set validation performed with NIR data showed 100% of correctly classified samples. Moreover, a satisfying percentage of correct classification in cross-validation was obtained for the electronic devices: the average values of correctly classified samples were 81.83% and 78.76% for electronic nose and electronic tongue, respectively. CONCLUSION NIR spectroscopy was shown to be a very reliable and useful tool to classify coffee samples in a fast, clean and inexpensive way compared to classical analysis, while the electronic devices could assume the role of investigating techniques to depict the aroma and taste of coffee samples. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]