Shengxin Li

Storage time significantly influences the aroma quality of peanut oil. In this study, gas chromatography–mass spectrometry (GC-MS) and gas chromatography–ion migration spectrometry (GC-IMS) were used to analyze the volatile flavor compounds of hot-pressed peanut oil baked at two temperatures (140 °C and 160 °C, denoted as OPO and RPO, respectively) during storage. The two methods detected 80 and 76 volatile flavor compounds, respectively, and principal component analysis (PCA) revealed clear distinctions between OPO and RPO during the storage period. Ten key aroma compounds were identified based on relative odor activity value (ROAV) analysis, including 3-methylbutanal, hexanal, heptanal, octanal, benzeneacetaldehyde, 3-ethyl-2,5-dimethylpyrazine,2-ethyl-6-methylpyrazine, acetylpyrazine, 2-methoxy- 4-vinylphenol, and acetic acid. During storage, the degradation and transformation of flavor compounds were more pronounced in RPO than in OPO. Physicochemical analyses showed increased acid and peroxide values, concomitant with decreased vitamin E and phytosterol content. Notably, these parameters changed more slowly in OPO than in RPO, confirming that OPO maintained superior quality over time. Correlation analysis suggested that changes in the aldehyde and pyrazine contents are key indicators of flavor and quality evolution in peanut oil during storage. This study provides insights into how baking temperature and storage time affect peanut oil aroma, elucidating the mechanisms of flavor variation and offering a theoretical basis for optimizing the flavor and quality of hot-pressed peanut oil.

Natural functional plant oils (FPOs) have been widely exploited due to their abundant biological activities. However, when exposed to oxygen, light, moisture, and heat, some limitations such as oxidative deterioration, impaired flavor, loss of nutritional value and volatile compounds, and decreased shelf life hinder the widespread application of FPOs in the food industry. Notably, the microencapsulation technique is one of the advanced technologies, which has been used to maintain the biological and physicochemical properties of FPOs. The present review provided a comprehensive overview of the nutrient compositions and functionality of FPOs, preparation techniques for microcapsules, and applications of microencapsulated FPOs (MFPOs) in the food industry. FPOs obtained from a wide range of sources were abundant in bioactive compounds and possessed disease risk mitigation and improved human health properties. The preparation methods of microencapsulation technology included physical, chemical, and physicochemical methods, which had the ability to enhance oxidative stability, functional, shelf life, and thermostability properties of FPOs. In this context, MFPOs had been applied as a fortification in sausage, meat, bakery, and flour products. Overall, this work will provide information for academic fields and industries the further exploration of food and nutriment products.

Seven fatty acids were detected by GC-MS in Xanthoceras sorbifolium Bunge seed oil extracted at different temperatures, including Palmitic acid C16:0, Stearic acid C18:0, Oleic acid C18:1, Eicosenoic acid C20:1, Docosenoic acid C22:1, Tetracosenoic acid C24:1, and Linoleic acid C18:2. The highest content of nervonic acid (NA) was found in Xanthoceras sorbifolium Bunge seed oil extracted at 70 °C. Three methods were selected to analyze the extraction rate of nervonic acid in Xanthoceras sorbifolium Bunge seed oil, including urea complexation, low-temperature solvent crystallization, and a combined treatment using these two methods. The final content of nervonic acid obtained was 14.07%, 19.66%, and 40.17%, respectively. The combined treatment method increased the purity of nervonic acid in Xanthoceras sorbifolium Bunge seed oil by 12.62 times. Meanwhile, thermogravimetric behavior analysis of samples extracted using different methods was conducted by thermogravimetric analyzer, which suggested that the thermal stability of the samples extracted by the combined treatment was enhanced. These results can provide a new process parameter and scientific basis for the extraction of NA. At the same time, FTIR and NMR were also used to characterize the combined extraction sample, and the structure of the samples was proved.

Prickly ash peel oleoresin (PPO) is a highly concentrated oil of Prickly ash essential oil and has a stronger aroma. However, its low water solubility, high volatility, difficulty in transport and storage, and decomposition by light, heat, and oxygen limit its wider application. To solve this problem, this study used freeze-drying or spray-drying, with soybean protein isolate (SPI) or gum Arabic (GA), combined with aqueous maltodextrin (MD) as the encapsulating agents to prepare four types of PPO microcapsules (POMs). Spray-dried microcapsules with GA as the encapsulating agent achieved a high encapsulation efficiency (EE) of 92.31 ± 0.31%, improved the thermal stability of the PPO, and had spherical morphology. (Headspace solid-phase microextraction/gas chromatography–mass spectrometry) HS-SPME/GC-MS detected 41 volatile compounds in PPO; of these, linalool, β-myrcene, sabinene, and D-limonene were identified as key flavor components. Principal component analysis (PCA) effectively distinguished the significant differences in flavor between PPO, spray-dried SPI/MD microcapsules (SS), and spray-dried GA/MD microcapsules (SG). During 15 days of air-exposure, the loss of flavor from SG (54.62 ± 0.54%) was significantly lower than PPO (79.45 ± 1.45%) and SS (57.55 ± 0.36%). During the air-exposure period, SG consistently had the highest antioxidant capacity, making it desirable for PPO packaging, and expanding its potential applications within the food industry.

Volatile compounds (VOCs) present in the oil extracted from yellow horn seeds were first analyzed using GC-IMS and GC-O-MS at varying roasting temperatures. A total of 97 VOCs were detected using GC-IMS, while 77 were tentatively identified using GC-O-MS. Moreover, both methods allowed the identification of 24 VOCs, of which the type of aldehydes is the most abundant. Combining the results of GC-IMS, GC-O-MS, OAVs, and VIP, it was concluded that hexanal, 2,5-dimethylpyrazine, heptanal, 2-pentylfuran, 1-hexanol, and 1-octen-3-ol were the key aroma compounds. The PLS-DA and OPLS-DA models have demonstrated the ability to discriminate between different oil roasting temperatures with high accuracy. The roasting temperature of 160 °C was found to yield the highest content of main aroma substances, indicating its optimality for yellow horn seed oil production. These findings will prove beneficial for optimizing industrial production and enhancing oil aroma control.