Coffee leaf valorisation into functional wheat flour rusk: their nutritional, physicochemical, and sensory properties.

Coffee leaves are currently emerging as a promising agri-food resource rich in phenolics. This study aims to valorise coffee leaf powder (CLP) by incorporating it in refined wheat flour rusk formulations and analyse its physio-chemical, rheological, functional and sensory characteristics. The progressive replacement of CLP improved the dietary fibre (2.51 ± 0.2%), ash (1.09 ± 0.11%), and water absorption capacity (59.7 ± 0.1%) of the flours. It considerably enhanced the falling number and sedimentation values of the flour blends while decreased the loaf volume. Progressive increase in the dietary phenolics (232.21-435.19 mg/100 g), chlorogenic acid (6.0-7.5 mg/100 g), and ABTS antioxidant activity (963.89-1607.25 µMTEAC/g) of the rusks was observed upon CLP addition. Rusks with 3% CLP were found to have significantly acceptable physical and sensory characteristics. Thus, supplementation of CLP in rusk helps in valorising coffee leaves besides providing a functional bakery product to the coffee industry. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05927-z.

Influence of milk fat on the physicochemical property of nanoencapsulated curcumin and enhancement of its biological properties thereof.

Curcumin, bioactive from turmeric Curcuma longa, has been known for its therapeutic properties. However, its lipophilic nature and poor bioavailability are the constraints to harnessing its properties. Encapsulation in nano-size helps to alleviate the constraints and enhance its biological properties due to its higher surface area. The study aims to encapsulate curcumin in a nanometer size range by solubilizing in lipid (milk fat) and using milk protein as a water-soluble carrier. The lipid:curcumin ratio (1:0.05, 1:0.1, 1:0.2, 1.5:0.1, 1.5:0.2, 2.0:0.1 and 2:0.2% (w/w)) produced nanoemulsion with droplets sizes 30-200 nm. The sample containing lipid: curcumin, as 1.0:0.05 resulted in an encapsulation efficiency of 92.6%, and its binding interaction with the carrier, was KD = 4.7 µM. A high solubility of curcumin in milk fat and digestion during in vitro lipolysis increased its bioaccessibility. A simulated gastro-intestinal in vitro studies showed that cumulative release percentage of nanoencapsulated curcumin was 60% at pH 7.4 compared to 0.8% of native curcumin. The anti-microbial property of nanoencapsulated curcumin was more potent than native curcumin against food pathogenic organisms such as S. aureus, B. cereus, E. coli, B. subtilis, P. aeruginosa, P. aeruginosa, C. violaceum. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05684-5.

Valorization of coffee leaves as a potential agri-food resource: bio-active compounds, applications and future prospective.

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.

New trends in specialty coffees - "the digested coffees".

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.

Microbial ecology and functional coffee fermentation dynamics with Pichia kudriavzevii.

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.

Green coffee nanoparticles: optimisation, in vitro bioactivity and bio-release property.

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.

The chemistry of chlorogenic acid from green coffee and its role in attenuation of obesity and diabetes.

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.

Microencapsulation of antioxidant phenolic compounds from green coffee.

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.

Fermentative recovery of lipids and proteins from freshwater fish head waste with reference to antimicrobial and antioxidant properties of protein hydrolysate.

Effectiveness of fermentation using lactic acid bacteria (LAB) for recovering lipids and proteins simultaneously from freshwater fish head (FWH) was evaluated. Three different proteolytic LAB (Pediococcus acidilactici NCIM5368, Enterococcus faecium NCIM5335 and Pediococcus acidilactici FD3) isolated from fish processing wastes were employed in the fermentation process. The fermentation conditions involved 10 % (w/w) glucose, 2 % (w/w) NaCl and 10 % (v/w) LAB cultures at 37 °C. The process resulted in 38.4 % of degree of hydrolysis (in case proteins) and a recovery of 63.6 % of the oil present in the material. The fermentation process did not affect the fatty acid profile of lipids. The hydrolyzed protein rich fermentation liquor exhibited DPPH radical scavenging activity (EC50 - 5.1 mg protein) as well as antagonistic properties towards several bacterial and fungal pathogens. The minimum inhibitory concentrations (MIC) of fermentated liquor (with E. faecium NCIM5335 as starter) were 10 and 12 mg/ml for Listeria monocytogenes and Salmonella itridicus, respectively. A higher MIC (60 and 96 mg/ml for Aspergillus ochraceus and Penicillium chrysogenum, respectively) was observed in case of fungal pathogens. Both the oil and protein hydrolysate rich liquor from fish head can be used as biofunctional ingredients in both human food as well as livestock feed formulations.

Functioning of Saccharomyces cerevisiae in honey coffee (Coffea canephora) and their effect on metabolites, volatiles and flavor profiles.

Post-harvesting and microbial activity of coffee play a critical role in the metabolites and the sensory quality of the brew. The pulped natural/honey coffee process is an improvised semi-dry technique consisting of prolonged fermentation of depulped coffee beans excluding washing steps. The starter culture application in coffee industry plays an important role to enhance the cup quality. This work focuses on the fermentation of pulped natural/honey Robusta coffee with a starter culture (Saccharomyces cerevisiae MTCC 173) and the identification of fermentation patterns through 1H NMR, microbial ecology, volatomics and organoleptics of brew. Fermentation was accelerated by yeast populace (10 cfu log/mL) for 192 h. Principal compound analysis performed on 1H NMR led to the investigation of metabolites such as sugars, alkaloids, alcohols, organic acids and amino acids. Detection of some sugars and organic acids represented that the starter cultures imparted few metabolic changes during the process. A major activity of sugars in fermentation with 83.3 % variance in PC 1 and 16.7 % in PC 2 was observed. The chemical characteristics such as carbohydrates (41.88 ± 0.77 mg/g), polyphenols (34.16 ± 0.79 mg/g), proteins (58.54 ± 0.66 mg/g), caffeine (26.54 ± 0.06 mg/g), and CGA (21.83 ± 0.04 mg/g) were also evaluated. The heatmap-based visualization of GC-MS accorded characterization of additional 5 compounds in treated (T) coffee contributing to sweet, fruity and caramelly odor notes compared to untreated (UT). The sensory outlines 72.5 in T and 70.5 in UT scores. Preparation of honey coffee with Saccharomyces cerevisiae is the first report, which modulated the flavor and quality of coffee.