Fructose as a daily sweetener is widely recognized as a risk catalyst for nonalcoholic fatty liver disease (NAFLD). The aim of current study is to evaluate the effects and molecular mechanism by which polyphenol-rich loquat fruit extract (LFP) prevents NAFLD in mice fed 30% fructose water (HF) for 8 weeks. Administration of LFP to HF-fed mice mitigated abnormal body weight, disordered lipid metabolism, oxidative stress, and inflammation through a mechanism regulated by the AKT, ChREBP/SREBP-1c, Nrf2, and TLR4/MyD88/TRIF pathways. LFP caused a significant decrease in the endotoxin content (16.67−12.7 EU/mL) in the liver of HF-fed mice. LFP not only improved HF-induced breakage of the intestinal barrier via interacting with tight junction proteins (ZO-1, occludin), mucin, and immunoreaction in the colon but also maintained normal colonic Firmicutes/Bacteroidetes ratios and the relative abundance of Veillonella in HF-fed mice. Our results suggest that LFP may serve as a nutritional agent for protecting liver in HF-fed mice.

The current study evaluated the effects of vacuum drying on the whole polyphenol profile of loquat fruit, including extractive and nonextractive polyphenols. Absorbance analysis determined that total polyphenol content and antioxidant levels were higher in loquat fruit vacuum dried at 140 °C than in loquat fruit vacuum dried at 70 °C. The results of ultra‐HPLC–triple quadruple mass spectrum analysis showed that 15 phenolic acids and 17 flavonoids were found in dried loquat fruit. Multivariate integrative (MINT) sparse partial least square‐discriminant analysis showed that vacuum drying affects the polyphenol profile of loquat fruit. Co‐analysis of principal component analysis, partial least square‐discriminant analysis, and orthometric partial least square‐discriminant analysis revealed that vacuum drying mainly changed the content of chlorogenic acid, cryptochlorogenic acid, protocatechuic acid, phloretin, and hesperidin in loquat fruit. Chlorogenic acid (12.020 to 39.153 µg/g d.b. [dried base weight]), the main polyphenol in dried loquat fruit, was degraded to caffeic acid (0.028 to 2.365 µg/g d.b.) and protocatechuic acid (0.014 to 18.285 µg/g d.b.) during vacuum drying. Moreover, vacuum drying also induced the isomerization of chlorogenic acid into cryptochlorogenic acid (1.628 to 12.737 µg/g d.b.). These results might be used to develop dried loquat fruit with high levels of polyphenols and antioxidant activity. Practical Application Interests in polyphenols of loquat fruit had increased greatly because of their possible role in health benefits. This work provided a holistic insight in the effects of vacuum drying on polyphenols profile of loquat fruit. Current results have contributed to the development of vacuum‐drying method, which produced loquat fruit rich in polyphenols. Furthermore, it also suggested that multivariate analysis was a feasible method to reveal the important changes of polyphenols profile during food processing.

Mulberry is a health-promoting fruit with abundant phenolic compounds. The effects of vacuum drying (VD) and vacuum freeze-drying (VFD) on oxidation resistance and polyphenols, including extractable and non-extractable phenols, were compared in the present work. The total polyphenols and antioxidant capacity of mulberry fruits treated with VFD were higher than those treated with VD. Thirteen phenolic compounds in fresh and dried mulberry fruits were identified and quantified by UPLC-QqQ/MS. The content of extractable phenol was significantly higher than that of non-extractable phenol. In addition, correlation analysis showed that flavonoids cyanidin-3-O-glucoside and phloretin were closely related to the total polyphenols and antioxidant activity. These results provide the basis for further development of dried mulberry products containing high content of total polyphenols and antioxidant activity.