Effect of extraction ph and temperature on the physicochemical properties and pectin yield from mango peel (Mangifera indica L.)

Objective: To evaluate the effect of the pH and extraction temperature on the pectin yield from mango (Mangifera indica) peel, cultivar Banilejo, and its physicochemical properties. Design/methodology/approach: Pectin extraction was done by acid hydrolysis, using hydrochloric acid and ethyl alcohol to precipitate and purify. A randomized design with a factorial arrangement was used, evaluating the effect of pH (1.5, 2.0, and 2.5) and temperature (70, 80, and 90 ºC) on the yield and quality of pectin. Quality was determined by measuring pH, viscosity and moisture content, ash, methoxyls, and esterification degree. Their means were compared using Tukey's test at 95 % confidence. Results: The best results were obtained at pH 2.0 and 80 ºC, reporting an 18.159 % yield, 6.766 % moisture, 2.630 % ash, 0.085 Pa.s of viscosity, 26.307 % methoxyl, and 64.753 % esterification. Study limitations/implications: The different treatment combinations demonstrate that pH, ash, methoxyl content, and esterification degree vary as a function of the assessed pH and extraction temperatures; while viscosity, moisture and yield were not influenced by these variables. Findings/conclusions: It is concluded that mango peel is a viable source to obtain quality pectin.

Green Husk of Walnuts (Juglans regia L.) from Southern Italy as a Valuable Source for the Recovery of Glucans and Pectins

Walnut green husk is an agricultural waste produced during the walnut (Juglans regia L.) harvest, that could be valued as a source of high-value compounds. In this respect, walnut green husks from two areas of Southern Italy (Montalto Uffugo and Zumpano), with different soil conditions, were investigated. Glucans and pectins were isolated from dry walnut husks by carrying out alkaline and acidic extractions, respectively, and then they were characterized by FT-IR, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The colorimetric method for the enzymatic measurement of α- and β-glucans was performed. The maximum total glucan yield was recovered from Montalto walnut husks (4.6 ± 0.2 g/100 g DM) with a β-glucan percentage (6.3 ± 0.4) higher than that calculated for Zumpano walnut husks (3.6 ± 0.5). Thermal analysis (DSC) confirmed the higher degree of crystallinity of glucans from Zumpano. The pectin content for Montalto husks was found to be 2.6 times that of Zumpano husks, and the esterification degree was more than 65%. The results suggested that J. regia L. green husks could be a source of glucans and pectins, whose content and morphological and thermal characteristics were influenced by different soil and climate conditions.

Potato Starch Extrusion and Roasting with Apple Distillery Wastewater as a New Method for Resistant Starch Production

Potato starch was extruded and roasted with apple distillery wastewater to produce starch esters substituted with malic acid residues. The starch esterification degree was higher at the higher roasting temperatures. Starch modification contributed to its darker color, its increased resistance to the action of amylolytic enzymes, and its decreased solubility and heat of phase transition. The changes in the other starch properties examined depended on the extrusion and roasting temperatures. The process, which was conducted without a chemical agent—in this case, the process of starch extrusion and roasting with apple distillery wastewater—should be deemed a novel method for resistant starch production.

Characterization of pectin from tongka langit banana peels with various extraction temperature

Banana peel waste can be used in the food industry as a source of pectin. Pectin can be obtained from the extraction process tongka langit banana peel. This research's objective was to characterize pectin's properties extracted from banana tongka langit peel with different extraction temperatures. A completely randomized experimental design with 3 level treatment extraction temperature of banana tongka langit peel, i.e., 80°, 85°, and 90°C, with three replicates was applied in this research. The properties evaluated, including equivalent weight, methoxyl content, galacturonate acid, esterification degree, yield, moisture content, and ash content. Result showed that equivalent weight (3104,3 mg, 1084,0 mg, and 699,8 mg), methoxyl content (3,25%, 3,87%, and 5,44%), galacturonate acid (24,56%, 38,06%, and 56,08%), esterification degree (76,02%, 57,45%, and 55,05%), moisture content (11,39%, 10,79%, and 9,85%), ash (4,42%, 5,11%, and 6,47%)), and yield (8,37%, 8,80%, and 9,20%).

Ferulated Pectins from Sugar Beet Bioethanol Solids: Extraction, Macromolecular Characteristics, and Enzymatic Gelling Properties

Pectin from sugar beet (Beta vulgaris L.) (SBP) was extracted from a sugar beet waste (SBW) registering a 4.4% (w/w) yield. SBP presented a weight-average molar mass of 459 kDa, galacturonic acid content of 52.2%, and a low esterification degree (30%). The macromolecular characteristics of SBP revealed a flexible and extended coil chain conformation. The main neutral sugars in SBP were galactose (20.7%), mannose (5.0%), and arabinose (3.60%) while ferulic acid (FA) content was 2.1 µg·mg−1 sample. FA remained in the SBP chain mainly in RG I region even after suffering both, industrial processing and harsh weathering conditions. Consequently, SBP formed covalent gels induced by laccase. Covalent cross-linking content (dimers and trimer of FA) was 0.97 mg·g−1 SBP. The 8-5′, 5-5′, and 8-O-4′ dimers of FA isomers proportions were 75, 17, and 8%, respectively. SBP gels at 4% (w/v ) registered storage (G′) and loss (G″) moduli final values of 44 and 0.66 Pa, respectively. SBP gels were soft and adhesive according to texture profile analysis. Scanning electron microscopy analysis of SBP lyophilized gels revealed an imperfect honeycomb-like structure with 4.5 ± 1.4 µm average cavities diameter.

Characteristics of Pectin Extracted from Cocoa Pod Husks

Cocoa plant husks is one of the source of pectin. Pectin in the food industry is used as thickener, gel agent and stabilizer. The aim of this study was to determine the characteristics of the pectin from cocoa pod husks with variation in temperature and extraction times. In this study the extraction of pectin from cocoa pod husk was carried out with hydrochloric acid solvent, with 40, 60 and 80 minutes extraction times at 65oC, 80oC, and 95oC. The results showed that the extraction temperature (65oC, 80oC, and 95oC) and extraction time (40, 60, and 80 minutes) had no significant effect on metoxyl content, galacturonat acid, equivalent weight, and pectin content, but the extraction time had a significant effect on the acetyl number and the degree of esterification. The highest yield of pectin was obtained at extraction temperature of 80oC for 60 minutes. The pectin content in cocoa pod husk is larger than the content in banana skin. The characteristics of cocoa pod husk pectin powder are brown, with moisture content 10.56-11.96%, ash content 6.82-8.97%, methoxyl content 3.51-4.86%, galacturonic acid content 41.38-88.40%, esterification degree 10.76-19.96%, acetyl number 14.55-20.90%, equivalent numbers 663.83-1549.22, pectin content 9.52-19.51 and yield 5.55- 7.70%. IR Spectrum showed that there was no difference in the functional groups between standard, commercial, and pectin extracted at different temperatures.

Modelling the Extraction of Pectin towards the Valorisation of Watermelon Rind Waste

Watermelon is the second largest fruit crop worldwide, with great potential to valorise its rind waste. An experimental design was used to model how extraction parameters (temperature, pH, and time) impact on the efficiency of the process, purity, esterification degree, monosaccharide composition and molar mass of watermelon rind pectin (WRP), with an insight on changes in their structural properties (linearity, branching degree and extraction severity). The models for all responses were accurately fitted (R2 > 90%, lack of fit p ≥ 0.05) and experimentally validated. At optimum yield conditions, WRP yield (13.4%), purity (540 µg/g galacturonic acid) and molar mass (106.1 kDa) were comparable to traditional pectin sources but showed a higher branching degree with longer galactan side chains and a higher protein interaction. Harsher conditions (pH 1) generated purer homogalacturonan fractions with average molar masses (80 kDa) at the expense of yield, while mild extraction conditions (pH ≥ 2) produced highly branched entangled pectin structures. This study underlines novel compositional features in WRP and the possibility of producing novel customized pectin ingredients with a wider potential application scope depending on the targeted structure.

Design, microwave synthesis, and molecular docking studies of catalpol crotonates as potential neuroprotective agent of diabetic encephalopathy

Catalpol has gained increasing attention for its potential contributions in controlling glycolipid metabolism and diabetic complications, which makes used as a very promising scaffold for seeking new anti-diabetic drug candidates. Acylation derivatives of catalpol crotonate (CCs) were designed as drug ligands of glutathione peroxidase (GSH-Px) based on molecular docking (MD) using Surfex-Docking method. Catalpol hexacrotonate (CC-6) was synthesized using microwave assisted method and characterized by FT-IR, NMR, HPLC and HRMS. The MD results indicate that with the increasing of esterification degree of hydroxyl, the C log P of CCs increased significantly, and the calculated total scores (Total_score) of CCs are all higher than that of catalpol. It shows that CCs maybe served as potential lead compounds for neuroprotective agents. It was found that the maximum Total_score of isomers in one group CCs is often not that the molecule with minimum energy. MD calculations show that there are five hydrogen bonds formed between CC-6 and the surrounding amino acid residues. Molecular dynamics simulation results show that the binding of CC-6 with GSH-Px is stable. CC-6 was screened for SH-SY5Y cells viability by MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay, the result indicates CC-6 can effectively reverse SZT induced cells apoptosis with dose-dependent manner, which can indirectly show that CC-6 is a potential neuroprotective agent.

Characterization and Bioactivity Test of Pectin from Musa balbisiana Peel Extracted using Various Acid Solvents

Banana (Musaceaea) is one of the highest production fruits in Indonesia, which amounted to 7,162,685 tons in 2017. Banana peel waste produced can reach 40% of the total production of fresh bananas. Kepok banana peel contains a lot of nutrients and pectin. Pectin levels in banana peel ranged from 1.92% to 3.25% of dry weight. This study aims to characterize pectin from kepok banana peel (Musa balbisiana) extracted using nitric acid, citric acid, and HCl and screening potential of pectin bioactivity based on LC50 values. The highest pectin yield was obtained from extraction using pH 4 citrate buffer which was 3.68 ± 1.23%. In general, the characteristics of the best pectin from kepok banana peel are pectin extracted with HNO3 pH 4 with methoxyl degree 3.74 ± 0.34%, galacturonate content 87.64 ± 8.36%, and esterification degree 24.24 ± 0.098%. Based on the LC50 value the pectin extraction results can be classified into two, namely commercial pectin and pectin HCl pH 1.5 which is low bioactivity (LC50 > 100 ppm), and pH 4 HNO3 pectin and pH 4 citrate buffer pectin which has high bioactivity (LC50 ≤ 30 ppm). Keywords: Cytotoxicity, galakturonat, kepok banana pectin, methoxyl