Cocoa pod husks are a waste generated during the processing of cocoa beans. We aimed to explore the enzymatic extraction of pectin using cellulases. The extraction process was optimized using a central composite design (CCD) and analyzed by response surface methodology (RSM). The parameters optimized were feedstock concentration (%), enzyme dosage (µL/g), and time (h). Three dependent variables were studied: pectin yield (g/100 g dry husk) (R² = 97.02), galacturonic acid content (g/100 g pectin) (R² = 96.90), and galacturonic acid yield (g/100 g feedstock) (R² = 95.35). The optimal parameters were 6.0% feedstock concentration, 40 µL g⁻¹ of enzyme, and 18.54 h, conditions that produced experimentally a pectin yield of 10.20 g/100 g feedstock, 52.06 g galacturonic acid/100 g pectin, and a yield 5.31 g galacturonic acid/100 g feedstock. Using the chemical extraction method, a yield of 8.08 g pectin/100 g feedstock and a galacturonic acid content of 60.97 g/100 g pectin were obtained. Using assisted sonication, a pectin yield of 8.28 g/100 g feedstock and a galacturonic acid content of 42.77 g/100 g pectin were obtained. Enzymatically optimized pectin has rheological and physicochemical features typical of this biomaterial, which provides an interesting alternative for the valorization of cocoa husks.

Cocoa pod husks (CPH) and cocoa bean shells (CBS) are the main by-products of the cocoa industry and a source of bioactive compounds. These residues are not completely used and thrown in the fields without any treatment, causing environmental problems. Looking for a holistic valorization, the aim of this work was first to deeply characterize CPH and CBS in their chemical composition, amino acid, and fatty acid profiles, as well as their application as antioxidants. CBS had a high level of protein (17.98% DM) and lipids (16.24% DM) compared with CPH (4.79 and 0.35% DM respectively). Glutamic acid and aspartic acid were the predominant amino acids. The total phenolic compounds (TPC) detected in the ethanolic extracts of CPH and CBS were similar to pyrogallol as the main detected polyphenol (72.57 mg/L). CBS ethanolic extract showed a higher antioxidant activity than CPH. Both extracts increased the oxidation stability of soybean oil by 48% (CPH) and 32% (CBS). In addition, alkaline pretreatment of CPH was found suitable for the release of 15.52 ± 0.78 g glucose/L after subsequent saccharification with the commercial enzyme Cellic^®. CTec2. Alkaline hydrolyzed and saccharified CPH (Ahs-CPH) was assessed for the first time to obtain polyhydroxy alkanoate (PHAs) and bioethanol. Ahs-CPH allowed the growth of both Cupriavidus necator DSM 545 and Saccharomyces cerevisiae Fm17, well-known as PHA- and bioethanol-producing microbes, respectively. The obtained results suggest that such agricultural wastes have interesting characteristics with new potential industrial uses that could be a better alternative for the utilization of biomass generated as million tons of waste annually.

The present research evaluated the antioxidant, antimicrobial and in vitro coloring capacity of extracts with different polarity obtained from avocado seeds (Persea americana Mill cv. Lorena). Besides, avocado oil was extracted from the residual mesocarps of P. americana Mill Hass cultivar by Soxhlet methodology, and the physicochemical properties of the extracted oil, as well as its fatty acid composition, were evaluated. Both the colorant and the avocado oil were used as supplies for a liquid soap type formulation. The antioxidant activity of the colorant extracts was determined by DPPH whereby water extracts showed the highest activity among the treatments. None of the extracts showed antimicrobial activity against Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922. The iodine value (177.52 cg I2 g-1) indicated that the avocado oil obtained has a high degree of unsaturation, and the Saponification index had a value of 190.74 mg KOH g-1. The colorant extracted with NaOH (L*=0.15, a*=0.05, and b*=-0.44) from the seeds was completely stable in a liquid soap matrix at pH 6.2 during one month of storage. This analysis suggests that it has high opportunities in the soap and cosmetic industry.

The current study sought to determine the potential of cacao pod husks for energy use. Biogas potential, the kinetics of anaerobic digestion at bench scale, and physicochemical characterisation of materials were evaluated for cacao pod husks (CPH), depectinised cacao pod husks (CPH-D), and cacao pod husks treated by Pleurotus spp. (CPH-DF). These materials showed accumulated biogas productions of 314.86 ±4.45 l·kg ⁻¹ VS ⁻¹ , 369.49 ±15.98 l·kg ⁻¹ VS ⁻¹ , and 342.52 ±10.98 l·kg ⁻¹ VS ⁻¹ , respectively. The calorific values in CPH-DF, CPH, and CHP-DF were 17.65 MJ·kg ⁻¹ , 15.43 MJ·kg ⁻¹ , and 17.21 MJ·kg ⁻¹ , respectively. These values indicate that the evaluated materials have a high potential to be used as biofuels.