Utilizing Coffee Pulp and Mucilage for Producing Alcohol-Based Beverage

Perspectives on carboxylates generation from Ecuadorian agro-wastes

Carboxylates generation from banana (peel and pulp), coffee, and cacao fermentation agro-waste, upon uncontrolled and controlled pHs of 6.6 (heat-driven methanogens inactivation) and 5.2 (pH inactivation), was studied. Regarding volatile fatty acids (VFAs), acetic was the highest for cocoa (96.2 g kg-1TVS) at pH 4.5. However, butyric was relevant for banana pulp (90.7 g kg-1TVS), at controlled pH 6.6. The highest medium chain fatty acid (MCFAs) level was hexanoic (cocoa, 3.5 g kg-1TVS), while octanoic reached a maximum of 2.8 g kg-1TVS for coffee at pH 6.6. At pH 5.2 MCFAs yield was relatively low. Uncontrolled pH conditions, using banana resulted in superior VFAs production compared to controlled conditions. Thus, pH became a determining variable when deciding the time and kind of carboxylic acid to be recovered. The bacterial community at the end of the chain elongation process was dominated by phyla Firmicutes, and Clostridium as the most common genera.

Mucilage polysaccharide as a plant secretion: Potential trends in food and biomedical applications

Current trends are shifting away from using synthetic compounds in favor of discovering new natural component sources that will allow them to create goods that are healthful, environmentally friendly, sustainable, and profitable. The food industry, in light of these trends, has opted to look for safe natural ingredients that will allow the production of low-fat, artificial-additive-free, gluten-free, prebiotic, and fortified foods. Similarly, the pharmaceutical and medical industries have attempted to apply natural ingredients to address the challenges related to biomaterials more efficiently than synthetic ingredients. Against this background, plant mucilage has proven to be a polysaccharide with excellent health features and technological properties, useful for both food and biomedical applications. Many studies have shown that its inclusion in different food matrices improves the quality of the products obtained under appropriate reformulations. At the same time, plant mucilage has been indicated to be a very interesting matrix in biomedical field especially tissue engineering applications since it has been emerged to favor tissue regeneration with its highly biocompatible structure. This concise review discusses the most recent advances of the applications of plant mucilage in different foods as well as its recent use in biomedical field. In this context, firstly, a general definition of mucilage was made and information about plant-based mucilage, which is frequently used, about the plant parts they are found in, their content and how they are obtained are presented. Then, the use of mucilage in the food industry including bakery products, meat emulsions, fermented dairy products, ice cream, and other foods is presented with case studies. Afterwards, the use of plant mucilage in the biomedical field, which has attracted attention in recent years, especially in applications with tissue engineering approach such as scaffolds for tissue regeneration, wound dressings, drug delivery systems and pharmaceutical industry was evaluated.

Coffee by-products: An underexplored source of prebiotic ingredients

Consumers' demand for foods with high nutritional value and health benefits has fueled the development of prebiotic foods. In coffee industry, cherries transformation into roasted beans generates a large amount of waste/by-products (pulp/husks, mucilage, parchment, defective beans, silverskin and spent coffee grounds) that usually end up in landfills. The possibility to use coffee by-products as relevant sources of prebiotic ingredients is herein ascertained. As a prelude to this discussion, an overview of pertinent literature on prebiotic action was conducted, including on biotransformation of prebiotics, gut microbiota, and metabolites. Existing research indicates that coffee by-products contain significant levels of dietary fiber and other components that can improve gut health by stimulating beneficial bacteria in the colon, making them excellent candidates for prebiotic ingredients. Oligosaccharides from coffee by-products have lower digestibility than inulin and can be fermented by gut microbiota into functional metabolites, such as short-chain fatty acids. Depending on the concentration, melanoidins and chlorogenic acids may also have prebiotic action. Nevertheless, there is still a lack of in vivo studies to validate such findings in vitro. This review shows how coffee by-products can be interesting for the development of functional foods, contributing to sustainability, circular economy, food security, and health.

Production of Coffee Cherry Spirits from Coffea arabica Varieties

Coffee pulp, obtained from wet coffee processing, is the major by-product accumulating in the coffee producing countries. One of the many approaches valorising this underestimated agricultural residue is the production of distillates. This research project deals with the production of spirits from coffee pulp using three different Coffea arabica varieties as a substrate. Coffee pulp was fermented for 72 h with a selected yeast strain (Saccharomyces cerevisiae L.), acid, pectin lyase, and water. Several parameters, such as temperature, pH, sugar concentration and alcoholic strength were measured to monitor the fermentation process. Subsequently, the alcoholic mashes were double distilled with stainless steel pot stills and a sensory evaluation of the products was conducted. Furthermore, the chemical composition of fermented mashes and produced distillates were evaluated. It showed that elevated methanol concentrations (>1.3 g/L) were present in mashes and products of all three varieties. The sensory evaluation found the major aroma descriptor for the coffee pulp spirits as being stone fruit. The fermentation and distillation experiments revealed that coffee pulp can be successfully used as a raw material for the production of fruit spirits. However, the spirit quality and its flavour characteristics can be improved with optimised process parameters and distillation equipment.

Effects of pretreatment and air drying temperature on Noni fruit powder

The plant Morinda citrifolia L. (Noni) has been the subject of several recent research due to its positive impact on the treatment and prevention of a variety of diseases. Noni fruits contain a variety of phytochemicals, including flavonoid, polyphenol, and triterpenoid saponin. This study aimed to determine the best pre-treatment (including blanching, soaking in ascorbic acid solution and metabisulfite solution) and air-drying temperature (50, 60, 70, and 80 °C) to maximize the total polyphenol content (TPC), flavonoid content (TFC), and triterpenoid saponin contents (TSC) of the resultant Noni fruit powder. The results revealed that pre-soaked Noni fruit samples in ascorbic acid or metabisulfite solution before air-drying at 60 °C were beneficial in preserving TPC, TFC, and TSC. TPC, TFC, and TSC losses increased as drying temperatures (70 and 80 °C) rose. The optimum sample was held at five different relative humidity conditions until they attained weight equilibrium. The results indicated that the sorption isotherm curve of the Noni powder was the sigmoid shape and fitted with the BET and GAB models.

Coffee Pulp, a By-Product of Coffee Production, Modulates Gut Microbiota and Improves Metabolic Syndrome in High-Carbohydrate, High-Fat Diet-Fed Rats

Waste from food production can be re-purposed as raw material for usable products to decrease industrial waste. Coffee pulp is 29% of the dry weight of coffee cherries and contains caffeine, chlorogenic acid, trigonelline, diterpenes and fibre. We investigated the attenuation of signs of metabolic syndrome induced by high-carbohydrate, high-fat diet in rats by dietary supplementation with 5% freeze-dried coffee pulp for the final 8 weeks of a 16-week protocol. Coffee pulp decreased body weight, feed efficiency and abdominal fat; normalised systolic blood pressure, left ventricular diastolic stiffness, and plasma concentrations of triglycerides and non-esterified fatty acids; and improved glucose tolerance in rats fed high-carbohydrate, high-fat diet. Further, the gut microbiota was modulated with high-carbohydrate, high-fat diet and coffee pulp supplementation and 14 physiological parameters were correlated with the changes in bacterial community structures. This study suggested that coffee pulp, as a waste from the coffee industry, is useful as a functional food for improving obesity-associated metabolic, cardiovascular and liver structure and function, and gut microbiota.

Aroma-Active Compounds in Robusta Coffee Pulp Puree-Evaluation of Physicochemical and Sensory Properties

Wet coffee processing generates a large amount of coffee pulp waste that is mostly disposed of in the processing units. To reduce this waste and the associated environmental burden, an alternative strategy would be to exploit the coffee pulp to produce a durable and stable consumable product. Accordingly, a puree produced from Robusta coffee pulp was investigated in relation to its physicochemical and sensory properties. After thermal and chemical stabilization, the obtained puree (pH 3.6) was found to exhibit a multimodal particle size distribution, shear-thinning behavior, and lower discoloration, as well as an antioxidant capacity of 87.9 µmol_TE/g_DM. The flavor of the puree was examined by sensory evaluation and the corresponding analyses of aroma-active volatile compounds, as determined using aroma extract dilution analyses (AEDA) and gas chromatography-mass spectrometry/olfactometry (GC-MS/O). The puree was characterized by dominant fruity (4.4), floral (3.4), citrusy (3.3) and hay-like (3.3) odor impressions. The aroma-active compounds were predominantly aldehydes, acids, and lactones, whereby (E)-β-damascenone, geraniol, 4-methylphenol, 3-hydroxy-4,5-dimethylfuran-2(5H)-one, and 4-hydroxy-3-methoxybenzaldehyde exhibited the highest flavor dilution (FD) factor (1024), thereby indicating their high impact on the overall aroma of the puree. This study demonstrates an approach to stabilize coffee pulp to produce a sweet, fruity puree with comparable physical properties to other fruit purees and that can be used as a new and versatile flavoring ingredient for various food applications.