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Coffee oligosaccharides (COS) are novel sources of prebiotics comprising manno-oligosaccharides, galacto-oligosaccharides, arabinoxylan-oligosaccharides, and cello-oligosaccharides. These oligosaccharides function as prebiotics, antioxidant-dietary fiber owing to important physicochemical and physiological properties, adjuvants, pharma, nutraceutical food, gut health, immune system boosting, cancer treatment, and many more. Research suggests COS performs prebiotic action, as it enhances gut health by promoting beneficial bacteria in the colon and releasing functional metabolites such as SCFAs. However, research on COS concerning other metabolic illnesses is still lacking. Among various production strategies, pretreatment and enzymatic hydrolysis are preferred for the production of COS. Functional oligosaccharides can add value to coffee waste and reduce the environmental impact of coffee manufacturing, besides providing more options for healthy and active ingredients. This review updates COS, production, bio-activity, their role as a functional food, food supplements/natural food additives, prebiotics and many applications of health sectors. Research is desirable to extend information on COS and their bio-activity, besides in vivo and clinical trials, to assess their effects in prior human formulations into the food and therapeutic arena., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Specialty coffee can be developed by the application of explicit microorganisms or starters to obtain desired fermentation. In the present study, natural fermentation (NF) of Arabica coffee was carried out spontaneously, the other set was inoculated with Pichia kudriavzevii (Y) starter culture (isolated, identified and mass cultured). The effect of microbial fermentation, metagenomics, production of functional metabolites, volatiles and their sensorial aspects were studied. The bioprocess illustrated cohesive interface of coffee nutrients and microbial communities like Mycobacterium, Acinetobacter, Gordonia, etc., in NF, Lactobacillus and Leuconostoc were prevailing in Y. The Pichia and Rhodotorula dominated in both the groups. The bioactivity of bacteria and fungi induced complex changes in physicochemical features like pH (4.2-5.2), Brix° (9.5-3.0), and metabolic transition in sugar (3.0-0.7%), alcohol (1.4-2.7%), organic acids modulating flavour precursors and organoleptics in the final brew. In the roasted bean, Y exhibited higher sugar (42%), protein (25%), polyphenol (3.5%), CGA (2.5%), caffeine (17.2%), and trigonelline (2.8%) than NF. The volatile profile exhibited increased flavour molecules like furans, ketones, and pyrazines in Y, besides lactone complexes. The organoleptics in Y were highlighted with honey, malt and berry notes. P. kudriavzevii coffee fermentation could be beneficial in specialty coffee production and enhancement of distinct characteristic flavours., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Main Conclusion: This article intends to summarize all the up-to-date information on coffee leaves, rendering it to be used as a potential agri-food resource in the growing functional foods and pharma industries. Coffee leaves have been processed for herbal tea and ethno-medicine since centuries in the parts of the world where coffee is grown traditionally. Currently, interest in the valorisation of coffee leaves for its application in the food industry is proliferating and the research related to it is scanty and, therefore, worthwhile to congregate. The current review compromises the botanical description, chemical composition, bio-actives and ethnomedicinal properties of coffee leaves. It encompasses the existing pharmacological studies on coffee leaves including the anti-oxidant, anti-inflammatory and anti-obesity activities to pave path for future research. Furthermore, applications and patents associated with coffee leaves in different fields such as therapeutic agents, beverages, packaging material, tobacco substitute etc. have been summarized. The investigation reveals that, despite of many patents on coffee leaves only few products could reach the worldwide market; also in spite of coffee leaves having a rich ethno-medicinal use the study on its pharmacological activities are scarce which creates a huge scope to carry out in-vitro and in-vivo research on its various bio-activities. Future insights reflecting the supplementary research regarding the sensory attributes, changes in phytochemical composition, flavour development and product formulations which is vital are also discussed. In conclusion, this review addresses the breach and specifies the requirements to convert the existing knowledge into commercialized food products with functional properties. Thus, coffee leaves being a copious resource of bio-actives serve as a potential agri-food resource and a promising future in the emerging functional food and nutraceutical industry., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Specialty coffee has gained immense popularity for its unique flavor and improved quality. There are large varieties of coffee trending every day due to the widened demand. Still, specialty coffee holds its place for its distinct processing inside the animal digestive system. Specialty coffees are also considered the most expensive due to coffee varieties with novelty in processing which leads to limited availability and less productivity. The digested coffee's uniqueness and rarity led to higher consumer demand, which paved the way for animal abuse in captivity and the production of fake authenticity to tackle the increased market requirement. In the context of coffee processing through conventional methods, the application of enzymes and microbes has brought about an improvement in coffee fermentation. Much research has been focused on the isolation of microbial cultures from the animal excreta and gastrointestinal tract. This review emphasizes the types of specialty coffee, its uniqueness compared to the traditional varieties, the bio-processing method of specialty coffee inside the animal gut and its taste profile.

An overview of green coffee, the unroasted bean enriched with antioxidants, is presented in the following article. Green coffee beans are known to have a higher content of chlorogenic acid (CGA) with potential health benefits like activity against hypertension, diabetes, obesity, etc. There are three major classes of chlorogenic acids present in green coffee beans, namely: caffeoylquinic acid (CQA), di-caffeoylquinic acid (diCQA) and feruloylquinic acid (FQA). Another pivotal component of the green beans is caffeic acid. A compilation of the different research studies and reviews pertaining to the diverse biomolecules present in the green coffee, their structure and the different sources of CGA is presented. The traditional and modern methods of the extraction of CGA are also studied. Green coffee upon roasting develops its aromatic characteristics but the flavor development comes with a reciprocation of reduced chlorogenic acid content. Thus, the effect of processing is also addressed. There are numerous studies conducted to show the health benefits associated with the consumption of green coffee out of which, anti-diabetic and anti-obesity effects are particularly concentrated in this article.

Nanoencapsulation by spray drying was performed to protect and preserve antioxidant rich dietary polyphenols from green coffee beans. Nano-encapsulation of green coffee was done using maltodextrin as wall material. The nanoparticles were further characterised by zetasizer, differential scanning colorimetry, X-ray diffraction, In vitro gastric intestinal studies and storage stability. Optimal nanoparticles were obtained at a drying temperature of 125 °C and 2:1 Mwall/Mcore ratio (10% w/w maltodextrin), provided better encapsulation yield (40% w/w) and 70 ± 5% (w/w) encapsulation efficiency with 82.34 nm particle size, -28.8 mV zeta-potential. The In-vitro bioactivity of nanoparticles ensured 80 ± 2% (w/w) of chlorogenic acid availability in a controlled release in the intestine. Storage stability of nanoparticles under varied temperature was remarkably improved compared to non-encapsulated green coffee extract. However, the results indicated that the potential benefits of using maltodextrin coated green coffee nanoparticles for controlled release of Chlorogenic acid and sufficient antioxidative protection during prolonged period.

Green coffee is a prime source of antioxidants to functional food and nutraceuticals. Arabica and Robusta varieties were screened and decaffeinated using ethyl lactate and extracted with a polar solvent to obtain chlorogenic acid (CGA) enriched green coffee extract (GCE). The physicochemical qualities (moisture, pH, particle size, and color) and bioactive compounds (total phenolics, chlorogenic acid, and caffeine) of GCE were assessed. The GCE had 12.78 ± 2.1 mg GAE g -1 phenolics and 10.98 mg g -1 chlorogenic acid (CGA). To improve the stability of CGA, the GCE encapsulated by spray drying using maltodextrin (MD) and skim milk (SM) as coating agent individually and in combination. Physicochemical, antioxidant properties, and biofunctionalities of microparticles were evaluated. Highest encapsulation efficiency of GCE with maltodextrin (1:1) was 86%±3 with the smaller particle size (2.3 ± 0.1 µm). Under the simulated gastric juice and bile salts solution, microencapsulation provided significantly better protection compared to non-encapsulated GCE. MGE elicits use as adjuvant/supplements in food, fortified for nutraceuticals and pharmaceuticals.

Gallic acid (3,4,5-trihydroxybenzoic acid) was produced by microbial biotransformation of coffee pulp tannins by Penicillium verrucosum. Gallic acid production was optimized using response surface methodology (RSM) based on central composite rotatable design. Process parameters such as pH, moisture, and fermentation period were considered for optimization. Among the various fungi isolated from coffee by-products, Penicillium verrucosum produced 35.23 µg/g of gallic acid on coffee pulp as sole carbon source in solid-state fermentation. The optimum values of the parameters obtained from the RSM were pH 3.32, moisture 58.40%, and fermentation period of 96 hr. Gallic acid production with an increase of 4.6-fold was achieved upon optimization of the process parameters. The results optimized could be translated to 1-kg tray fermentation. High-performance liquid chromatography (HPLC) analysis and spectral studies such as mass spectroscopy (MS) and (1)H-nuclear magnetic resonance (NMR) confirmed that the bioactive compound isolated was gallic acid. Thus, coffee pulp, which is available in enormous quantity, could be used for the production of value-added products that can find avenues in food, pharmaceutical, and chemical industries.