Valorization of walnut processing waste as a novel resource: Production and characterization of pectin

Unlocking the Potential of Food Waste: A Review of Multifunctional Pectins

This review comprehensively explores the multifunctional applications of pectins derived from food waste and by-products, emphasizing their role as versatile biomaterials in the medical-related sectors. Pectins, known for their polyelectrolytic nature and ability to form hydrogels, influence the chemical composition, sensory properties, and overall acceptability of food and pharmaceutical products. The study presents an in-depth analysis of molecular parameters and structural features of pectins, such as the degree of esterification (DE), monosaccharide composition, galacturonic acid (GalA) content, and relative amounts of homogalacturonan (HG) and rhamnogalacturonan I (RG-I), which are critical for their technofunctional properties and biological activity. Emphasis is placed on pectins obtained from various waste sources, including fruits, vegetables, herbs, and nuts. The review also highlights the importance of structure-function relationships, especially with respect to the interfacial properties and rheological behavior of pectin solutions and gels. Biological applications, including antioxidant, immunomodulatory, anticancer, and antimicrobial activities, are also discussed, positioning pectins as promising biomaterials for various functional and therapeutic applications. Recalled pectins can also support the growth of probiotic bacteria, thus increasing the health benefits of the final product. This detailed review highlights the potential of using pectins from food waste to develop advanced and sustainable biopolymer-based products.

Fabrication and characterization of pectin-zein nanoparticles containing tanshinone using anti-solvent precipitation method

Tanshinone compounds are secondary metabolites which their application in food and pharmaceutical industry is limited due to the low solubility in water and sensitivity to heat. This study aimed to develop a novel biopolymer nanocarriers system based on pectin/zein for the encapsulation of tanshinone compounds using the anti-solvent precipitation method. The concentration of pectin and mass ratio of tanshinone/zein in the final formulation of nanoparticles were optimized. According to the results, a pectin concentration of 1 g/L and a tanshinone/zein ratio of 0.1:1 g/g were considered the optimal nanoparticle formulation. The resulting nanoparticles exhibited a spherical core-shell structure, with approximate values for size, zeta potential, TSI, and encapsulation efficiency of 132 ± 0.002 nm, -38.6 ± 0.019 mV, 0.600 ± 0.084, and 79.41 ± 0.62 %, respectively. The FTIR test confirmed the presence of hydrophobic, hydrogen, and electrostatic interactions among the constituents within the nanoparticles. Additionally, XRD and DSC tests verified the amorphous nature of the nanoparticles. Morphological examination conducted through TEM, and SEM revealed the characteristics of the resulting nanoparticles. Furthermore, this carrier system significantly enhanced the solubility of tanshinone compounds in water.

NADES assisted integrated biorefinery concept for pectin recovery from kinnow (Citrus reticulate) peel and strategic conversion of residual biomass to L(+) lactic acid

The present study aims to establish an integrated strategy for valorization of kinnow peel waste. A total of ten natural deep eutectic solvents (NADESs) were exploited for extraction of pectin. The highest yield of pectin enriched material was reported 35.66 % w/dw using choline chloride-Maltose based NADES. The extraction process parameters and chemical composition of NADES influenced the yield and different associated physico-chemical attributes of the pectin enriched material. All the recovered pectin enriched materials found to be composed of low methoxy pectin (degree of methylation: 18.41-40.26 %) and galacturonic acid (GalA) content was in range of 67.56-78.22 %. The Principal Component Analysis (PCA) was used to categorise isolated pectin enriched materials based on similarities and differences. The liquid fraction upon pectin extraction presented a considerable amount of fermentable sugar which was further utilized for lactic acid production by microbial intervention. The microbial strain Lactobacillus amylophilus GV6 was exploited for lactic acid fermentation where the highest yield reached 55.59 g/L. A sustainable and straight-forward biorefinery concept was developed for extraction of pectin enriched material and lactic acid production from kinnow peel waste with potential application in food and biotechnological sectors.

Towards Valorization of Food-Waste-Derived Pectin: Recent Advances on Their Characterization and Application

Pectin, a natural biopolymer, can be extracted from food waste biomass, adding value to raw materials. Currently, commercial pectin is mostly extracted from citrus peels (85.5%) and apple pomace (14.0%), with a small segment from sugar beet pulp (0.5%). However, driven by high market demand (expected to reach 2.12 billion by 2030), alternative agro-industrial waste is gaining attention as potential pectin sources. This review summarizes the recent advances in characterizing pectin from both conventional and emerging food waste sources. The focus is the chemical properties that affect their applications, such as the degree of esterification, the neutral sugars' composition, the molecular weight, the galacturonic acid content, and technological-functional properties. The review also highlights recent updates in nutraceutical and food applications, considering the potential use of pectin as an encapsulating agent for intestinal targeting, a sustainable biopolymer for food packaging, and a functional and emulsifying agent in low-calorie products. It is clear from the considered literature that further studies are needed concerning the complexity of the pectin structure extracted from emerging food waste raw materials, in order to elucidate their most suitable commercial application.

Valorization of wastes and by-products of nuts, seeds, cereals and legumes processing

Wastes and by-products of nuts, seeds, cereals and legumes carry a unique potential for valorization into value-added ingredients due to their protein, dietary fiber, antioxidant, vitamin and mineral contents. The most crucial factor in the recovery of value-added ingredients and bioactives from the wastes and by-products is the utilization of the most efficient extraction technique. This work is an overview of the classification of wastes and by-products of nuts, seeds, cereals and legumes processing, the methods used in the extraction of valuable compounds such as proteins, dietary fibers, phenolics, flavonoids and other bioactives. This chapter provides insights on the promising applications of extracted ingredients in various end products. A special emphasis is given to the challenges and improvement methods for extraction of value-added compounds from wastes and by-products of nuts, seeds, cereals and legumes processing.

Microwave-assisted valorization and characterization of Citrus limetta peel waste into pectin as a perspective food additive

Machine learning techniques were employed to evaluate the effect of process parameters viz. microwave power (100 W, 300 W, 600 W); pH (1, 1.5, 2); and microwave time (the 60 s, 120 s, 180 s) on the pectin yield from Citrus limetta peel. A fourth-order polynomial function of 66.60 scales was used by the Support Vector Regression (SVR) model at an epsilon (ε) value of 0.003. The co-efficient of determination (R2) and root mean square error-values for training data and test data were 0.984; 0.77 and 0.993; 0.66 respectively. At optimized conditions, microwave power 600 W, pH 1, and time 180 s the best yield of 32.75% was obtained. The integrity of pectin skeletal was confirmed with FTIR and 1H NMR spectrums. The physicochemical analysis revealed that CLP is a high-methoxyl pectin (HMP) with a 63.20 ± 0.88% degree of esterification, 798.45 ± 26.15 equivalent weight, 8.06 ± 0.62% methoxyl content, 67.93 ± 3.36 AUA content, 6.27 ± 0.27 g water/g pectin WHC, 2.68 ± 0.20 g oil/g pectin OHC, low moisture, ash and protein content of 6.85 ± 0.10%, 3.87 ± 0.10% and 2.61 ± 0.06% respectively, which can be utilized as a food additive. Therefore, pectin extraction from Citrus limetta peel using a greener technique like MAE is an eco-friendly, time-saving approach to transform waste into a versatile food additive.

Encapsulation of Vitamin B12 by Complex Coacervation of Whey Protein Concentrate-Pectin; Optimization and Characterization

Vitamin B12 (VB12) is one of the essential vitamins for the body, which is sensitive to light, heat, oxidizing agents, and acidic and alkaline substances. Therefore, the encapsulation of VB12 can be one of the ways to protect it against processing and environmental conditions in food. In this work, the influence of pectin concentration (0.5−1% w/v), whey protein concentrate (WPC) level (4−8% w/v) and pH (3−9) on some properties of VB12-loaded pectin−WPC complex carriers was investigated by response surface methodology (RSM). The findings showed that under optimum conditions (1:6.47, pectin:WPC and pH = 6.6), the encapsulation efficiency (EE), stability, viscosity, particle size and solubility of complex carriers were 80.71%, 85.38%, 39.58 mPa·s, 7.07 µm and 65.86%, respectively. Additionally, the formation of complex coacervate was confirmed by Fourier-transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM). In addition, it was revealed that the most important factor in VB12 encapsulation was pH; at a pH < isoelectric point of WPC (pH = 3), in comparison with higher pH values (6 and 9), a stronger complex was formed between pectin and WPC, which led to an increase in EE, lightness parameter, particle size and water activity, as well as a decrease in the zeta-potential and porosity of complex carriers.

Construction of double-network hydrogel based on low methoxy pectin/polyvinyl alcohol and its structure and properties

In this study, an interpenetrating double-network hydrogel (LMP/AA/PVAH) was prepared based on low methoxy pectin (LMP), acrylic acid (AA) and polyvinyl alcohol (PVA). The first rigid network of chemical crosslinking was constructed via free radical polymerization of LMP and AA, and the second of ductile physical crosslinking network was constructed via cyclic freeze-thaw of PVA. The first cycle hardness and elasticity of the LMP/AA/PVAH significantly increased from 13.08 N and 0 to 24.28 N and 0.79, respectively, when the second network structure was constructed in the hydrogel by PVA. Besides, the PVA network might enhance the ductile and limit the swelling of hydrogel. In addition, the adsorption properties of LMP/AA/PVAH were evaluated by adsorption of methylene blue (MB). The adsorption behavior of MB by LMP/AA/PVAH conformed to the pseudo-second-order kinetic model. Besides, after 4 cycles of adsorption, there was no significant difference in adsorption capacity of LMP/AA/PVAH. The results showed that LMP/AA/PVAH had good reusability.

Enterprise Activity Modeling in Walnut Sector in Ukraine

The main goal of this study was to provide a critical analysis of the oil and fat sub-complex for deep walnut processing, to determine and compare the profitability of enterprises’ activities under different business models for implementation in the agro-food value chain. The latter was considered as an important factor for the development of the domestic market of walnuts and export opportunities. Business modeling of the enterprise activity in the oil and fat sub-complex for deep walnut processing was carried out. The stages of production and marketing activities of the enterprise from the garden planting or the purchase of the processed raw materials to the sale of the processed raw materials and products obtained from walnut processing depending on the chosen business model were considered. A comparative analysis of profitability of the enterprise activity and absolute values of income and profitability indicators under various business models of the enterprise activity were shown. The most cost-effective business-model entailed the combination of walnut production and its processing, which will provide profitability of up to 4640.32% in the 20th year of the project implementation. The results of the given study are intended for the agricultural enterprises of central region of Ukraine.