The use of coffee leaves as a novel beverage has recently received consumer interest, but there is little known about how processing methods affect the quality of final product. We applied tea (white, green, oolong and black tea) processing methods to process coffee leaves and then investigated their effects on phytochemical composition and related antioxidant and anti-inflammatory properties. Using Japanese-style green tea-processing of young leaves, and black tea-processing of mature (BTP-M) coffee leaves, produced contrasting effects on phenolic content, and associated antioxidant activity and nitric oxide (NO) inhibitory activity in IFN-γ and LPS induced Raw 264.7 cells. BTP-M coffee leaves also had significantly (P < .05) higher responses in NO, iNOS, COX-2, as well as a number of cytokines, in non-induced Raw 264.7. Our findings show that the age of coffee leaves and the type of processing method affect phytochemical profiles sufficiently to produce characteristic antioxidant and anti-inflammatory activities.

Coffee leaves have a long history for use as ethnomedicine and tea beverage by locals from countries where coffee plants grow. Recently, attentions have been paid to their health benefits to human beings because of abundant bioactive components in coffee leaves. However, the researches related to the bioactivities, applications, and the impacts of processing methods on the phytochemical composition and activities of coffee leaves are scarce. The reviews specific to coffee leaves in these aspects are rare too. Due to the growing interests to coffee leaves, in this review, the chemical compositions in coffee leaves and the influence of environmental conditions and processing methods on them were summarized. Furthermore, various applications of coffee leaves, including ethnomedicine, coffee leaf tea, therapeutic agent, packaging material, tobacco substitute, organic fungicide, personal hygienic products, and animal feed et al. were presented. The future prospects of coffee leaves are also discussed. In conclusion, coffee leaf is a very promising resource in the areas of food and industry, especially, in the beverage industry. The researches in understanding impacts of the processing methods on the phytochemicals, enzymes, bioactivities, and flavor of coffee leaves are highly needed.

• Ultrasound decreased the size and distribution of AuNPs. • Ultrasound increased the yield and the anti-inflammatory activity of AuNPs. • AuNPs synthesized using citrus peel extract under ultrasound are stable. • The IC₅₀ of AuNPs against nitric oxide was negatively correlated with ΔTPC. • Hesperidin is the major reductant in citrus peel extract for AuNPs synthesis.

Mangiferin is a potential candidate for use in nutraceutical and functional food applications due to its numerous bioactivities. However, the low bioavailability of mangiferin is a major limitation for establishing efficacy for use. This review describes current information on known food sources and factors that influence mangiferin contents, absorption, and metabolism features, and recent progress that has come from research efforts to increase the bioavailability of mangiferin. We also list patents that targeted to enhance mangiferin bioavailability. Mangifera indica L. is the major dietary source for mangiferin, a xanthone that varies widely in different parts of the plant and is influenced by many factors that involve plant propagation and post-harvest processing. Mangiferin absorption occurs mostly in the small intestine by passive diffusion with varying absorption capacities in different segments of the gastrointestinal tract. Recent research has led to the development of novel technologies to encapsulate mangiferin in nano/microparticle carrier systems as well as generate mangiferin derivatives to improve solubility and bioavailability. Preclinical studies reported that mangiferin < 2000 mg/kg is generally nontoxic. The safety and the increase in bioavailability are key limiting factors for developing successful applications for mangiferin as a nutritional dietary supplement or nutraceutical.