Spermidine, a natural autophagy inducer, has a variety of health effects, such as antitumor, antiaging, anti‐inflammation, cardiovascular protection, and neuromodulation. It has been a hot topic in the field of food processing, and current research findings suggest that spermidine‐rich foods may be used in intervention and prevention of age‐related diseases. In this article, recent findings on the safety, health effects, absorption and metabolism of spermidine were reviewed, and advances in food processing, including the raw materials evaluation, physical and chemical processing, and biological processing of spermidine, were highlighted. In particular, the core metabolic pathways, key gene targets, and efficient metabolic engineering strategies involved in the biosynthesis of spermidine and its precursors were discussed. Moreover, limitations and future perspectives of spermidine research were proposed. The purpose of this review is to provide new insights on spermidine from its safety to its food processing, which will advance the commercial production and applications of spermidine‐rich foods and nutraceuticals.

In this study, the influences of different proportions (0%, 5%, 10%, 15% and 20% w/w) of pomelo peel sponge layer insoluble dietary fibre (PP-IDF) on the technological quality, structural character and sensory evaluation of wheat dough and bread were studied. Results showed that the addition of PP-IDF improved the viscoelasticity of dough and reduced its enthalpy of freezing-thawing. Meanwhile, PP-IDF significantly improved the quality of bread during storage. Compared with the control, the 7-day moisture rate of bread containing PP-IDF increased by 3.50-6.80%, indicating that PP-IDF retarded the staling process of bread. Moreover, SEM images showed that the bread prepared using PP-IDF had a more heterogeneous crumb microstructure, and the higher the addition level of PP-IDF, the larger the void structure. The results of the texture profile analysis indicated that the hardness and chewiness of bread increased with the incorporation of PP-IDF, suggesting that the addition of PP-IDF had a negative effect on the texture property of bread. Furthermore, the sensory evaluation of bread was performed, and the taste of the bread was better when PP-IDF addition content was 5-10%. The results of this study revealed that PP-IDF had great potential for the development of innovative bread recipes.

Summary Drying pretreatments are usually considered as effective way to improve the quality of dried fruit products. The results of this research showed that the blanching (BL), ultrasonic (US) and freeze–thaw (FT) pretreatments could significantly shorten the drying time, and improve the rehydration capacity of the dried longan pulp. Compared with the control group (CK, without pretreatment), more irregular inner micropores were formed in the dried longan pulp treated with BL, US and FT. Besides, the brightness and yellowness of dried longan pulp with pretreatments were higher than those of the CK. The higher retention rates of total phenolic content (292.54 mg/100 g d.b.) and ascorbic acid (2.38 mg g−1 d.b.) were observed in the dried longan pulp treated with BL. Meanwhile, a higher chlorogenic acid content was found in the samples treated with FT (3.68 mg/100 g d.b.) and radio frequency (RF) (3.10 mg/100 g d.b.). Furthermore, the highest retention of a total free amino acid (1843.13 mg/100 g d.b) was exhibited by RF‐treated longan pulp. This work guides how pretreatments are applied prior to longan pulp drying.