Bioactive Compounds from Cocoa Husk: Extraction, Analysis and Applications in Food Production Chain

High potential extracts from cocoa byproducts through sonotrode optimal extraction and a comprehensive characterization

Cocoa pod husk (CPH) and cocoa bean shell (CBS) are by-products obtained during pre-processing and processing of cocoa beans. Several bioactive compounds have been identified in these by-products that can be used for commercial applications as a way to promote the circular economy. Therefore, the objective of this paper was to recover bioactive compounds from CPH and CBS by sonoextraction process, to determine the type, content, and antioxidant activity in optimized extracts. To achieve our purpose, an optimization strategy using Box-Behnken Design coupled response surface methodology (MRS) was applied. The extraction conditions were optimized. The results obtained for CBS were: TPC (193 mg GAE/g), TEAC (1.02 mmol TE/g), FRAP (1.02 mmol FeSO4/g) and ORAC (2.6 mmol TE/g), while for CPH, the reported values were: TPC (48 mg GAE/g), TEAC (0.30 mmol TE/g), FRAP (0.35 mmol FeSO4/g) and ORAC (0.43 mmol TE/g) under the optimized conditions: Time (XA): 15 min, Amplitude (XB): 80 %, Ethanol (XC): 50 %. The LC-ESI-qTOF-MS analysis results allowed the identification of 79 compounds, of which 39 represent the CBS extract, while 40 compounds were identified in CPH extract. To conclude, sonotrode based extraction could be considered as an efficient and fast alternative for the recovery of bioactive substances from CBS and CPH.

Improving the Composition and Bioactivity of Cocoa (Theobroma cacao L.) Bean Shell Extract by Choline Chloride-Lactic Acid Natural Deep Eutectic Solvent Extraction Assisted by Pulsed Electric Field Pre-Treatment

An environmentally friendly method for the release of cocoa bean shell (CBS) extracts is proposed in this paper. This work aims to investigate the effect of pulsed electric field (PEF) pre-treatment on subsequent solid-liquid extraction (SLE) of metabolites with choline chloride-lactic acid natural deep eutectic solvent (NaDES) and bioactivity of cocoa bean shell (CBS) extract. Two different media for PEF application were evaluated: water and chlorine chloride-lactic acid. Total polyphenols (TPC), total flavonoids (TFC), individual major compounds, and antioxidant and antibacterial activity of CBS extracts were assessed. The performance of PEF-assisted extraction was compared with SLE and ultrasound-assisted extraction (UAE). The proposed method improved the release of TPC up to 45% and TFC up to 48% compared with the conventional extraction. The CBS extract showed medium growth inhibition of Escherichia coli and high growth inhibition of Salmonella sp, Listeria monocytogenes, and Staphylococcus aureus. Thus, an extract with enhanced antioxidant and antibacterial properties was obtained.

Bioactive Compounds from Organic Waste

The reuse and reincorporation of waste are the principles of circular economies. Compost, biofuels, animal feed, dyes, and bioactive compounds can be obtained from the revaluation of organic waste. Research on this subject is scarce and limited to specific sectors, such as agriculture and agroindustry, leaving aside others that generate large quantities of organic waste, such as floriculture. The remains of these sectors have a low decomposition rate compared to other organic wastes. They are a source of bioactive compounds (e.g., essential oils, pigments, phenols) that can be reincorporated into the production chain of various industries. This review describes the composition of waste from agroindustry, agriculture, and floriculture, analyzing their potential revalorization as a source of bioactive compounds and an alternative supply source.

Chromatographic Fingerprinting of Cacao Pod Husk Extracts (Theobroma cacao L.): Exploring Antibacterial, Antioxidant, and Antidiabetic Properties with In Silico Molecular Docking Analysis

Natural drugs derived from plants are becoming more popular because of their apparent biological efficacy, affordability, and safety. A byproduct of cocoa farms, cocoa pod husk (CPH), is often disregarded yet contains an abundance of phenolic chemicals that have antimicrobial and antioxidant features, which has led to intensive investigation into possible biomedical applications. In order to identify crucial functional groups and phytochemical components, we carefully examined the 80% ethanol and dichloromethane extracts of CPH using gas chromatography-mass spectrometry (GC-MS) and HPLC. The antibacterial and antioxidant properties of such extracts and their impact on cytotoxicity and α-glucosidase were explored. According to our results, the 80% ethanol and dichloromethane extracts contained 19 and 12 phytochemical components, respectively. Interestingly, at 250 µg/mL, all CPH extracts showed strong antibacterial properties that totally prevented the bacterial growth. At 66.6% and 82.7%, respectively, the ethanol and dichloromethane extracts showed impressive antioxidant and DPPH scavenging capabilities where the ethanol extract showed a substantially lower IC50 value of 35.26 µg/mL than the dichloromethane extract, which had an IC50 value of 23.88 µg/mL. Furthermore, the α-glucosidase inhibitory effect of the dichloromethane extract was found to be better, as shown by its IC50 value of 126.5 µg/mL, which was lower than that of the ethanol extract at 151.3 µg/mL. The extracts' compatibility was verified by cytotoxicity tests, which revealed no appreciable alterations in the cell lines. Additionally, novel in silico molecular docking experiments were performed on 25 discovered compounds, providing insight into their possible bioactivity. Broad-spectrum activities of extracts were confirmed by molecular docking investigations aimed at interacting with α-glucosidase proteins. Our thorough analysis makes CPH extracts seem like the excellent candidates for biomedical uses. These results provide new insights into the therapeutic potential of CPH extracts and pave the way for the development of innovative medications and natural remedies.

Optimizing vacuum drying process of polyphenols, flavanols and DPPH radical scavenging assay in pod husk and bean shell cocoa

The objective of this study was to optimize different vacuum drying conditions for cocoa pod husk and cocoa bean shell in order to enhance these by-products for commercial applications. To carry out the optimization, the response surface methodology was applied using a Box-Behnken experimental design with 15 experiments for which different conditions of temperature (X1), drying time (X2) and vacuum pressure (X3) were established. The response variables were the content of total polyphenols, the content of flavanols and the radical scavenging activity evaluated in the extracts of the different experiments. Temperature (50-70 °C), drying time (3-12 h) and vacuum pressure (50-150 mbar) were considered as independent variables. The main factors affecting the response variables were temperature, followed by vacuum pressure. For the content of polyphenols, the optimal response values predicted for the cocoa pod husk was 11.17 mg GAE/g with a confidence limit (95%) of 9.05 to 13.28 mg GAE/g (optimal conditions: 65 °C, 8 h and 75 mbar), while for the cocoa bean shell cocoa was 29.61 mg GAE/g with a confidence limit (95%) of 26.95 to 32.26 mg GAE/g (optimal conditions: 50 °C, 5 h and 100 mbar). Therefore, results of this study suggest a high content of phenolic compounds obtained from these by-products that show relevance as functional ingredients for application in the food, nutraceutical, and cosmeceutical industries.

Changes in the cocoa shell dietary fiber and phenolic compounds after extrusion determine its functional and physiological properties

The influence of different extrusion conditions on the cocoa shell (CS) dietary fiber, phenolic compounds, and antioxidant and functional properties was evaluated. Extrusion produced losses in the CS dietary fiber (3-26%), especially in the insoluble fraction, being more accentuated at higher temperatures (160 °C) and lower moisture feed (15-20%). The soluble fiber fraction significantly increased at 135 °C because of the solubilization of galactose- and glucose-containing insoluble polysaccharides. The extruded CS treated at 160 °C-25% of feed moisture showed the highest increase of total (27%) and free (58%) phenolic compounds, accompanied by an increase of indirect (10%) and direct (77%) antioxidant capacity. However, more promising results relative to the phenolic compounds' bioaccessibility after in vitro simulated digestion were observed for 135°C-15% of feed moisture extrusion conditions. The CS' physicochemical and techno-functional properties were affected by extrusion, producing extrudates with higher bulk density, a diminished capacity to hold oil (22-28%) and water (18-65%), and improved swelling properties (14-35%). The extruded CS exhibited increased glucose adsorption capacity (up to 2.1-fold, at 135 °C-15% of feed moisture) and α-amylase in vitro inhibitory capacity (29-54%), accompanied by an increase in their glucose diffusion delaying ability (73-91%) and their starch digestion retardation capacity (up to 2.8-fold, at 135 °C-15% of feed moisture). Moreover, the extruded CS preserved its cholesterol and bile salts binding capacity and pancreatic lipase inhibitory properties. These findings generated knowledge of the CS valorization through extrusion to produce foods rich in dietary fiber with improved health-promoting properties due to the extrusion-triggered fiber solubilization.

Response Surface Methodological Approach for Optimizing Theobroma cacao L. Oil Extraction

Theobroma cacao L. (Cocoa) is an agricultural product that is economically valuable worldwide; it is rich in bioactive compounds such as phenolic compounds and flavonoids. These compounds are known for their anti-inflammatory, anticarcinogenic, antimicrobial, antiulcer, and immune-modulating properties. Cocoa powder and cocoa butter are the major cocoa seed products, and cocoa seed oil (CSO) is the least-studied cocoa seed product. CSO is used in several industries; therefore, optimizing the extraction of high-quality CSO is essential. We used response surface methodology (RSM) to optimize the restriction dies, temperature, and sieve size to achieve a high yield and quality of CSO. The quality of the CSO was assessed according to total phenolic content (TPC), acid, and peroxide values, fatty acid content, and nitric oxide free radical scavenging activity. The highest yield (actual value: 46.10%; predicted value: 45.82%) was observed with the following restriction parameters: die size: 0.8 cm, temperature: 40 °C, and sieve size > 1.4 mm. The 2FI model for CSO extraction, the pressing time, the reduced quadratic model for acid value, the reduced cubic model for peroxide value, and the TPC showed that the model was significant. Our study primarily reported the impact of sieve size, restriction die, and temperature on CSO yield, acid, peroxide values, TPC of the CSO, and the influence of pressing time on the quantity and quality of the CSO. The high yield of CSO was of relatively lower quality. The temperature affected the yield, acid, peroxide values, TPC, and the nitric oxide free radical scavenging activity. In comparison, the fatty acid composition of the CSO was not affected by the processing temperature or sieve size. The results indicated that the extraction conditions must be chosen based on the application of the extracted oil. Further studies are warranted to confirm the results and further analyze other influential parameters during CSO extraction.