Insight of Polyphenol Oxidase Enzyme Inhibition and Total Polyphenol Recovery from Cocoa Beans

Zein as an Effective Carrier for Hesperidin Delivery Systems with Improved Prebiotic Potential

Hesperidin is a polyphenol derived from citrus fruits that has a broad potential for biological activity and the ability to positively modify the intestinal microbiome. However, its activity is limited by its low solubility and, thus, its bioavailability-this research aimed to develop a zein-based hesperidin system with increased solubility and a sustained release profile. The study used triple systems enriched with solubilizers to maximize solubility. The best system was the triple system hesperidin-zein-Hpβ-CD, for which the solubility improved by more than six times. A significant improvement in the antioxidant activity and the ability to inhibit α-glucosidase was also demonstrated, due to an improved solubility. A release profile analysis was performed in the subsequent part of the experiments, confirming the sustained release profile of hesperidin, while improving the solubility. Moreover, the ability of selected probiotic bacteria to metabolize hesperidin and the effect of this flavonoid compound on their growth were investigated.

Impact of Fermentation and Pasteurization on the Physico-Chemical and Phytochemical Composition of Opuntia ficus-indica Juices

Opuntia ficus-indica fruits are a source of valuable compounds, presenting a high nutritional value and several health benefits. However, due to its low shelf life and increased production, there are considerable post-harvest losses of this cactus fruit. So, ways need to be found to drain the increased production of this fruit that is being wasted. The chemical composition of prickly pear makes it an appealing substrate for fermentation. This study investigates the production of fermented beverages produced from Opuntia ficus-indica cv 'Rossa' and evaluates the effects of different fermentation times (18 and 42 h) and post-fermentation pasteurization by high-pressure (500 MPa for 10 min) and temperature (71.1 °C for 30 s) on the physico-chemical and biological characteristics of the produced beverages. According to the results, the beverage produced from 48 h of fermentation has an alcohol content value of 4.90 ± 0.08% (v/v) and a pH of 3.91 ± 0.03. These values contribute to an extended shelf life and improved organoleptic characteristics compared to the sample fermented for 18 h. Additionally, the longer fermentation resulted in 50% fewer total soluble solids, 90% less turbidity, and lower pH when compared to the sample fermented for 18 h. Moreover, overall, high-pressure processing demonstrates better retention of "fresh-like" characteristics, along with higher levels of phytochemical compounds and antioxidant capacity, similar to those observed in the juice for SO^•- and NO^•-scavenging abilities.

Exploring the chemical composition and coloring qualities of cacao fruit epicarp extracts

Cacao pod husks (CHs), the most abundant by-product of cacao beans production, can potentially become a source of functional ingredients for the food, cosmetic, and pharmaceutical industries. Three pigment samples (yellow, red, and purple) from lyophilized and ground cacao pod husk epicarp (CHE), were isolated by ultrasound-assisted solvent extraction, with yields between 11 and 14 wt%. The pigments exhibited UV-Vis flavonoid-related absorption bands at 283 nm and 323 nm and, only for the purple extract, reflectance bands in the 400-700 nm range. As per the Folin-Ciocalteu method, the CHE extracts contain high yields of antioxidant phenolic compounds amounting to 161.6, 153.9, and 167.9 mg GAE per g extract for the yellow, red, and purple samples, respectively. Phloretin, quercetin, myricetin, jaceosidin, and procyanidin B1 were among the main flavonoids identified by MALDI-TOF MS. A biopolymeric bacterial-cellulose matrix can effectively retain up to 541.8 mg of CHE extract per g of cellulose in dry weight. Also, MTT assays revealed that CHE extracts are non-toxic and increase viability in cultured VERO cells.

Biochemical studies of enzyme-induced browning of African bush mango (Irvingia gabonensis) fruit pulp

The purpose of this study was to examine the biochemical properties of African bush mango (Irvingia gabonensis) pulp PPO. PPO was purified from I. gabonensis fruit pulp in three steps and characterized. A purification fold of 343 with specific activity of 216 U/mg and 13% recovery were obtained as well as molecular weight of 32.67 kDa was observed. The optimum pH and temperature were found to be pH 7.0 and 50 °C respectively while the enzyme showed instability at low pH 2-4 with total inactivation at pH 2 but maximal at pH 5-9 with remaining residual activity of 60-90%, whereas, total enzyme activity inactivation was observed at 90 °C. However, Cu²⁺, Fe²⁺ and Mg²⁺ enhanced the PPO activity but inhibited by Ca²⁺, Ba²⁺, K⁺ and Na⁺. Notably, purified PPO was inactivated completely by urea at concentration above 10 mM while K_m and V_max values were estimated to be 7.34 mM and 0.36 U/min for catechol, 10.76 mM and 0.30 U/min for _L-DOPA, and 14.90 mM and 0.26 U/min for tyrosine, respectively. The activity of PPO in I. gabonensis fruit and its juicy product could be controlled at high temperature in acidified medium.

Bioactive compounds and techno-functional properties of high-fiber co-products of the cacao agro-industrial chain

The cacao shell (CS) and cacao pod husk (CPH), two of the most promising high-fiber co-products of the cacao agro-industrial chain, were evaluated to determine their potential incorporation into food products. This research determined bioactive compounds and techno-functional properties of CS and CPH, and was evaluated the enzymatic inactivation by thermal treatments in CPH. We found that CS is rich in protein, lipids, dietary fiber (48.1 ± 0.3 g 100 gdw -1), and antioxidant molecules such as epicatechin (1.10 ± 0.02 mg g-1) and isoquercetin (1.04 ± 0.09 mg g-1). Moreover, in CS a positive effect of hydration mechanism occur; in fact, it was observed a reduction of Lightness (L∗) value and a remarkable color difference (ΔE∗,18.8 ± 0.7) (CIEL∗a∗b∗ color space), between hydrated and dry CS samples; so, it could be used as a potential natural colorant in foods. CPH resulted equally rich in dietary fiber (35.3-37.4%) and flavonoids (2.9 ± 0.1 mg RE g-1); in this co-product, the rapid enzymatic inactivation by thermal treatments was essential to obtain the highest antioxidant activity and polyphenols content; regarding the techno-functional properties, it was found that CPH flour had high hydration capacity, so CPH can use it as a replacement for emulsifiers or water holding additives while incorporating the fiber and abundantly found antioxidants.

Antioxidants in Cocoa

Cocoa beans are the seeds of the tropical tree Theobroma cacao L [...].

Preparative Separation of Procyanidins from Cocoa Polyphenolic Extract: Comparative Study of Different Fractionation Techniques

To provide further insight into the antioxidant potential of procyanidins (PCs) from cocoa beans, PC extract was fractionated by several methodologies, including solid phase extraction, Sephadex LH-20 gel permeation, and preparative HPLC using C18 and diol stationary phases. All the isolated fractions were analyzed by UHPLC-QTOF-MS to determine their relative composition. According to our results, classical techniques allowed good separation of alkaloids, catechins, dimers, and trimers, but were inefficient for oligomeric PCs. Preparative C18-HPLC method allowed the attainment of high relative composition of fractions enriched with alkaloids, catechins, and PCs with degree of polymerization (DP) < 4. However, the best results were obtained by preparative diol-HPLC, providing a separation according to the increasing DP. According to the mass spectrometry fragmentation pattern, the nine isolated fractions (Fractions II–X) consisted of exclusively individual PCs and their corresponding isomers (same DP). In summary, an efficient, robust, and fast method using a preparative diol column for the isolation of PCs is proposed. Regarding DPPH^• and ABTS^•+ scavenging activity, it increases according to the DP; therefore, the highest activity was for cocoa extract > PCs > monomers. Thereby, cocoa procyanidins might be of interest to be used as alternative antioxidants.