Quality evaluation of fresh pistachios (Pistacia vera L.) cultivars coated with chitosan/TiO2 nanocomposite
Fresh pistachios are rich in dietary fiber, minerals and unsaturated fatty acids, but they have a short shelf life. This investigation examined the effect of pre-harvest foliar application with chitosan (500 and 1000 mg. L-1), nano-chitosan (250 and 500 mg. L-1), and chitosan/TiO2 nanocomposite (250 and 500 mg. L-1) coating films on the postharvest physiology and storage of fresh pistachios (Pistacia vera cvs. Akbari and Ahmad Aghaei) cultivar during storage at 4 ± 0.5 °C. It was found that, fresh pistachios' shelf life could by increased by up to 30 days by the use of chitosan/TiO2 nanocomposite coating for foliar application. The decay index of the composite coated fruits was 4-6 % lower than that of the control group, and after 50-60 days the bacterial contamination appeared in cultivars; respectively. The nanocomposite treatments reduced the fruits weight between 30 and 40 %, which was 15 % higher that of than uncoated fruits. The pre-harvest application of chitosan/TiO2 coating reduced microbial contamination, weight loss, phenylalanine ammonialyase (PAL) activity and saturated fatty acids, and increased unsaturated fatty acids, antioxidant properties, sensory properties, essential minerals, superoxide dismutase (SOD), quality indicators and shelf life. These results demonstrated that the chitosan/TiO2 (250 and 500 mg. L-1) coating film effectively preserved the nutrient composition, sensory quality, nutritional value, antioxidant capacity and shelf life of fresh pistachio.
https://doi.org/10.1016/j.ijbiomac.2023.129055
Valorization of walnut green husk (Juglans regia L.) through sequential electrohydrodynamic extraction of pectin and phenolics: Process optimization and multidimensional analysis
This study aimed to optimize the extraction of pectin and phenolics from walnut green husk using the electrohydrodynamic method (EHD) and assess its impact on the chemical structure and properties of pectin. A comparative analysis was conducted with acidified water as the conventional extraction method. The results revealed significant improvements under the optimal EHD conditions (36.8 min, 17.5 kV, 90 °C), leading to a remarkable increase of over 64 % in pectin yield and >20 % in total phenolic content in half the extraction time. Chemical analysis showed that pectin samples contain 1.4-1.7 % ash, 3.6-4.6 % protein, over 90 % carbohydrates, and a galacturonic acid content ranging from 67.7 to 68.2 g/g. Both extraction methods yielded pectin with a high methoxyl degree, comparable thermal stability, and amorphous structure. EHD treatment resulted in reduced molecular weight, degree of esterification, water-holding capacity, and emulsion stability of pectin while enhancing its solubility and emulsion capacity. In summary, EHD treatment significantly improved extraction yield and changed the functionality of pectin, particularly in terms of emulsion activity. This alteration should be considered when utilizing pectin for specific applications. https://doi.org/10.1016/j.ijbiomac.2023.127545
Valorization of pistachio industrial waste: Simultaneous recovery of pectin and phenolics, and their application in low-phenylalanine cookies for phenylketonuria
This study introduces a sustainable approach to simultaneously produce pectin and phenolic compounds from pistachio industrial waste and applies them in the formulation of low-phenylalanine cookies. The co-optimization process was performed using the microwave-assisted technique and a Box-Behnken design, considering four variables and two responses: pectin yield and total phenolic content (TPC). The co-optimized condition (microwave power of 700 W, irradiation time of 210 s, pH level of 1.02, and LSR of 20 mL/g) resulted in a pectin yield of 15.85 % and a TPC of 10.12 %. The pectin obtained under co-optimized condition was evaluated for its physicochemical, structural, and thermal properties and the phenolic extract for its antiradical activity. Characterization of the pectin sample revealed a high degree of esterification (44.21 %) and a galacturonic acid-rich composition (69.55 %). The average molecular weight of the pectin was determined to be 640.236 kDa. FTIR and 1H NMR spectroscopies confirmed the structure of pectin, with an amorphous nature and high thermal stability observed through XRD and DSC analysis. Additionally, the extract exhibited significant antiradical activity comparable to butylated hydroxyanisole and ascorbic acid. The isolated ingredients were used to formulate low-protein, low-phenylalanine cookies for phenylketonuria patients. The addition of 0.5 % pectin and 1 mL/g extract led to increased moisture content (from 9.05 to 12.89 %) and specific volume (from 7.28 to 9.90 mL/g), decreased hardness (from 19.44 to 10.39 N × 102), and improved antioxidant properties (from 5.15 % to 44.60 % inhibition) of the cookies. Importantly, there was no significant increase observed in the phenylalanine content of the samples with pectin and extract addition. Furthermore, sensory evaluation scores demonstrated significantly higher scores for taste, odor, texture, and overall acceptability in cookies enriched with 0.5 % pectin and 1 mL/g extract, with scores of 4.53, 3.93, 4.40, and 4.60, respectively. https://doi.org/10.1016/j.ijbiomac.2023.126086
Isolation and characterization of micro and nanocrystalline cellulose fibers from the walnut shell, corncob and sugarcane bagasse.
The present study aims to extract and characterize the microcrystalline cellulose (MCC) present in different agro-industrial wastes such as walnut shells, corncob, and sugarcane bagasse. Moreover, it is also the aim of this study to convert MCCs to nanocrystalline cellulose fiber (NCCF), to demonstrate the difference in morphological, structural, thermal, and chemical natures. Corncob cellulose was observed to possess a loosely bounded linear bundle structure. Nanocrystalline cellulose fiber yield from walnut shell and sugarcane bagasse cellulose were higher than corncob cellulose. The thermal stability of cellulose was noted to be high for walnut shell NCCF. Nanocrystalline cellulose fiber of corncob and sugarcane bagasse was estimated to have a low thermal degradation temperature. All the MCCs and NCCFs produced from investigated cellulose sources were found to have type I cellulose. Functional group compositions of cellulose were observed to be intact for converted agro-based NCCF's.
Effects of Peanut Shell and Skin Extracts on the Antioxidant Ability, Physical and Structure Properties of Starch-Chitosan Active Packaging Films.
In this study, the antioxidant ability of peanut shell and skin extracts and their effects on the physical and structure properties of starch-chitosan film were investigated. The results showed that the DPPH radical scavenging ability of peanut skin extracts was significantly higher than the peanut shell extracts. This could be due to the rich rutin and 4-O-caffeoulquinic acid existed in the peanut skin extracts. When added the peanut skin and shell extracts into the starch-chitosan film, the apparent viscosity of film forming solution at 100 s-1 decreased. Moreover, water vapor permeability and swelling of film decreased with the addition of peanut skin and shell extracts. Two peanut extracts also increased the color L* and opacity of film. The tensile strength of film increased with the addition of peanut skin extracts, and decreased with peanut shell extracts. The addition of two extracts also resulted in the increase of endothermic temperature of starch-chitosan film. But there were no new peaks appeared in the FTIR image. Only the peaks at 3276 cm-1, 1382 cm-1, 1249 cm-1 shifted to 3273 cm-1, 1385 cm-1 and 1258 cm-1, which implied the peanut shell and skin extracts disturbed the hydrogen bond and vibration of molecular chain in film matrix.
Peanut oil cake-derived cellulose fiber: Extraction, application of mechanical and thermal properties in pineapple/flax natural fiber composites.
In this work peanut oil cake extracted Cellulose Micro Filler (CMF) is used for the advancement of mechanical and thermal properties in natural fiber composites. This fiber powder was used in enhancing the applications of Pineapple (P)/Flax (F) natural fiber epoxy composites. The X Ray Diffraction (XRD) results of CMF showed improved Crystalline Index (Crl) of 70.25° and crystalline size of 5.5 nm. FTIR results confirmed the rich cellulose content in functional groups of filler with peaks at 1058 cm-1, 1162 cm-1, 1370 cm-1 and 1428 cm-1. Mechanical results showed a positive impact with incorporation of CMF in PF hybrid fiber composites. Thermal stability results showed enhancement in the degradation temperature, residual %, endothermic peak and enthalpy by the incorporation of CMF. In the 30% PF combinations degradation temperature T50, T70, T70 enhanced from 387.73-391.08°, 434.81-454.81° and 468.91-553.36° by the filler substitution. Similarly residual % increased from 17.69-24.35%. The combination with 35% PF showed enhancement in degradation temperature, residual percentage, endothermic peak and enthalpy with filler addition up to 3%.
FT-IR spectroscopy and Morphological study of functionalized cellulosic fibers: Evaluation of their dyeing properties using biological Pistacia vera hulls by-product extract.
The repulsion between cellulose and anionic entities could be overcome by imparting cationic sites on its structure. In this work, we studied the treatment of cotton fabric with different amounts of chitosan bio-polymer (0.0125-0.075%), dimethyl diallyl ammonium chloride and diallylamin co-polymer (1-5%), alum (0.5-20 g/L), and sodium chloride (2-40 g/L) in order to improve their dyeing behaviors with an ecological extract of Pistacia vera hulls by-products. The chemical modification of the cellulosic fibers was confirmed using Fourier Transform Infra-Red (FT-IR) and Scanning Electron Microscopy (SEM). The unmodified and modified cellulosic samples were, then, dyed with Pistacia vera extract. The dyeing characteristics were assessed through the measurements of the color coordinates and the color strength. Results showed that the dyeing performance followed the order: Cotton-dimethyl diallyl ammonium chloride and diallylamin co-polymer (K/S = 9.6) > Cotton-Chitosan (K/S = 8.97) > Cotton-Alum (8.84) > Cotton-NaCl (K/S = 6.06) > Untreated cotton (K/S = 1.98). All dyed samples exhibited good fastness to washing, rubbing and light. Overall, it has shown in this study that the functionalization of cellulose structure could greatly improve its dyeing behavior depending on the cationic sites number.
Plant extracts such as pine nut shell, peanut shell and jujube leaf improved the antioxidant ability and gas permeability of chitosan films.
In order to develop the antioxidant and gas permeability packaging film, the effects of three plant extracts (pine nut shell, peanut shell and jujube leaf) on the physical, antioxidative and structural properties of chitosan based biodegradable films were studied. The results showed that three plant extracts improved the antioxidant capacity of films. The DPPH radical scavenging activity of chitosan-jujube leaf films increased by 3.8 times compared with the control films. The chitosan-pine nut shell films had the highest water vapor and oxygen permeability, while chitosan-peanut shell films showed greatest increase in CO2 permeability with a value of 1.71 × 104 cm3/(m2·24h) under standard test. In addition, three plant extracts reduced the homogeneity and caused porous structure of chitosan films. Chitosan-peanut shell films had the highest thermal stability compared with the control and other two films. X-ray diffraction and FTIR indicated three plant extracts changed the hydrogen bonding of film matrix and caused the changes of crystal and chemical structure. The study provided a reference for the preparation of polysaccharide-based active films with strong antioxidant and gas permeability.
High-methylated pectin from walnut processing wastes as a potential resource: Ultrasound assisted extraction and physicochemical, structural and functional analysis.
The ultrasound-assisted extraction of pectin from walnut processing waste was optimized by Box-Behnken design. The highest extraction yield (12.78±0.83%) was obtained at ultrasound power of 200 W, sonication time of 10 min, pH of 1.5 and LS ratio of 15 v/w. The resulting pectin in these conditions was rich in galacturonic acid (69.44%) and was high in degree of esterification (59.21%) which was confirmed by NMR and FTIR spectra. In addition, the molecular weight distribution analysis showed that the obtained pectin had a heterogeneous natural with low molecular weight (6.30-158.48 kDa). The XRD spectrum of the walnut pectin showed an amorphous structure with few crystalline portions. Furthermore, walnut green husk pectin had good emulsifying properties, water and oil holding capacities, and radical-scavenging activity. Given that the obtained result, the extraction of pectin from this by-product in addition to being able to reduce environmental problems, it can also provide financial benefits for the walnut production sector.
Antioxidant and hepatoprotective properties of dried fig against oxidative stress and hepatotoxicity in rats.
The aim of this study was to investigate the hepatoprotective effect and antioxidant role of dried fig (DF) (Ficus carica L.) against ethanol-induced oxidative stress. Experiment was designed as normal Control, 20% ethanol, 10% DF and 10% DF+20% ethanol groups. The hepatoprotective and antioxidant role of the dried DF supplementation feed against ethanol induced oxidatif stress were evaluated by liver histopathological changes, measuring liver damage serum enzymes (LDSE), antioxidant defense system (ADS) and malondialdehyde (MDA) content in various tissues of rats following the exposure of experimental for 50days. The biochemical analysis showed a considerable increase the LDSE in the ethanol group as compared to that of control group whereas, decreased in 10% DF+20% ethanol group as compared to that of ethanol group. In addition, the DF supplementation diet restored the ethanol-induced MDA and ADS towards to control. The hepatoprotection of DF is further substantiated by the almost normal histologic findings of liver in 10% DF+20% ethanol group against degenerative changes in ethanol group. The results indicated that the DF could be as important as diet-derived antioxidants and antihepatotoxicity in preventing oxidative damage in the tissues by inhibiting the production of ethanol-induced free radicals and hepatotoxicity in rats.