Arabinoxylo-oligosaccharides production from unexploited agro-industrial sesame (Sesamum indicum L.) hulls waste.

This work demonstrates that sesame (Sesamum indicum L.) hull, an unexploited food industrial waste, can be used as an efficient source for the extraction of hemicellulose and/or pectin polysaccharides to further obtain functional oligosaccharides. Different polysaccharides extraction methods were surveyed including alkaline and several enzymatic treatments. Based on the enzymatic release of xylose, arabinose, glucose, and galacturonic acid from sesame hull by using different enzymes, Celluclast®1.5 L, Pectinex®Ultra SP-L, and a combination of them were selected for the enzymatic extraction of polysaccharides at 50 °C, pH 5 up to 24 h. Once the polysaccharides were extracted, Ultraflo®L was selected to produce arabinoxylo-oligosaccharides (AXOS) at 40 °C up to 24 h. Apart from oligosaccharides production from extracted polysaccharides, alternative approaches for obtaining oligosaccharides were also explored. These were based on the analysis of the supernatants resulting from the polysaccharide extraction, alongside a sequential hydrolysis performed with Celluclast®1.5 L and Ultraflo®L of the starting raw sesame hull. The different fractions obtained were comprehensively characterized by determining low molecular weight carbohydrates and monomeric compositions, average Mw and dispersity, and oligosaccharide structure by MALDI-TOF-MS. The results indicated that sesame hull can be a useful source for polysaccharides extraction (pectin and hemicellulose) and derived oligosaccharides, especially AXOS.

Comprehensive structural and functional characterization of a new protein-polysaccharide conjugate between grass pea protein (Lathyrus sativus) and xanthan gum produced by wet heating.

The purpose of this work was to use a controlled wet-heating process to promote Maillard reaction (MR) between grass pea protein (GPPI) and xanthan gum (XG), and then analyse structural, functional and antioxidant properties of the conjugate (GPPI-XGCs). During heating, the degree of glycation of all conjugated samples was raised (up to 37.43 %) and, after heating for 24 h, the lightness of the samples decreased by 24.75 %. Circular dichroism showed changes in secondary structure with lower content of α-helix and random coil in conjugates. XRD patterns showed that MR destroyed the crystalline structure of the protein. In addition, Lys and Arg content of the produced conjugates decreased by 16.94 % and 6.17 %, respectively. Functional properties including foaming capacity and stability were increased by 45.17 % and 37.17 %, and solubility reached 98.88 %, due to the protein unfolding driven by MR. GPPI-XGCs showed significantly higher antioxidant activities with maximum ABTS-RS value of 49.57 %. This study revealed how MR can improve GPPI's properties, which can aid the food industry in producing a wide range of plant-based foods. Especially, among other characteristics, the foaming properties were significantly improved and the final product can be introduced as a promising foaming agent to be used in food formulation.

Development of lentil peptides with potent antioxidant, antihypertensive, and antidiabetic activities along with umami taste.

Lentil peptides have shown promising bioactive properties regarding the antioxidant activity and also inhibitory activity of angiotensin-I-converting enzyme (ACE). Sequential hydrolysis of proteins has shown a higher degree of hydrolysis with enhanced antioxidant and ACE-inhibitory activities. The lentil protein concentrate (LPC) was sequentially hydrolyzed using Alcalase and Flavourzyme at 2% w/w. The hydrolysate (LPH) was cross-linked (LPHC) or sonicated (LPHUS) and sequentially cross-linked (LPHUSC). Amino acid profile, molecular weight (MW) distribution, DPPH and ABTS radical scavenging activities (RSA; 7 mg/mL), ACE (0.1-2 mg/mL), α-glucosidase, and α-amylase inhibitory activities (10-500 µg/mL), and umami taste were determined. The highest DPPH RSA was obtained for LPH (68.75%), followed by LPHUSC (67.60%), and LPHUS (67.49%) while the highest ABTS RSA values were obtained for LPHC (97.28%) and LPHUSC (97.20%). Cross-linking and sonication led to the improvement of the ACE-inhibitory activity so that LPHUSC and LPHC had IC50 values of 0.23 and 0.27 mg/mL, respectively. LPHC and LPHUSC also indicated higher α-glucosidase inhibitory activity (IC50 of 1.2 and 1.23 mg/mL) compared to LPH (IC50 of 1.74 mg/mL) and LPHUS (IC50 of 1.75 mg/mL) while the IC50 value of acarbose indicated 0.51 mg/mL. Moreover, LPHC and LPHUSC exhibited higher α-amylase inhibitory activities (IC50 of 1.35 and 1.16 mg/mL) than LPHUS (IC50 of 1.95 mg/mL), and LPH (IC50 of 2.51 mg/mL) while acarbose had an IC50 value of 0.43 mg/mL. Umami taste analysis revealed that LPH and LPHC due to MW of 1.7 and 2.3 kDa and also high umami amino acids could be well considered as representative of meaty and umami analog flavors while indicating stronger antioxidant, antihypertension, and antidiabetic attributes.

Almond hulls waste valorization towards sustainable agricultural development: Production of pectin, phenolics, pullulan, and single cell protein.

This research aimed to valorize almond hulls based on a zero-waste strategy towards sustainable agricultural developments for the recovery and production of valuable compounds. For this purpose, the potential to produce four products, including pectin (AHP), phenolic compounds (AHPC), pullulan (PUL), and single-cell protein (SCP), was examined. The acidic extraction factors were optimized using a Box-Behnken design for the simultaneous extraction of AHP and AHPC, and the obtained results showed that the maximum AHP (26.32% w/w) and AHPC (6.97% w/w) yields were achieved at 90 °C, pH of 1.4, 58.65 min, and liquid-solid ratio (LSR) of 20.13 v/w as the optimum point. In the next step, the solid residues that remained from the AHP and AHPC extraction process (PESR) were treated with cellulase enzyme and ultrasound and were used for simultaneous microbial production of PUL (34.29-24.56 g/L) and biomass containing SCP (19.31-13.44% w/w). Furthermore, the obtained results showed that AHP was low methylated (26.40%), rich in galacturonic acid (67.88%), and high in molecular weight (595.299 kDa). Also, the investigations of structural properties of AHP and PUL confirmed the presence of chemical structures of these polysaccharides in the formed supernatants. In addition, the AHPC showed considerable antioxidant activity compared with ascorbic acid (ASC) and BHA.

Microwave treatment to modify textural properties of high protein gel applicable as dysphagia food.

The study aimed to formulate a high protein base as a dysphagia food and investigate the possibility of textural modification by applying microwave treatments. The formulated mixture contained 41.7% pea protein (dry basis), which exhibited shear thinning behavior. The application of microwave processing at 300, 500, and 700 W for 60, 120, and 180 s showed that at a higher level of energy induction by microwave, the hardness of the sample gradually increased from a fluid gel to a soft solid and more rigid levels. Processing at 300 and 500 W in the tested range showed that textural properties (hardness, adhesiveness, cohesiveness, springiness, gumminess, and chewiness) of the sample could be modulated within the recommended criteria for dysphagia food, providing the possibility of individualization of food texture for dysphagia disorder. Two main causes of these textural changes could be water evaporation and protein denaturation, in which, regarding the ratio of water evaporation to the size of textural changes, protein denaturation was thought to have the main impact on the phenomena.

Combined effects of octenylsuccination and beeswax on pullulan films: Water-resistant and mechanical properties.

In this study, to improve the water resistance properties of pullulan (PU) edible-films, the combination of the modification with octenyl succinic anhydride (OSA) and beeswax (BW) incorporation was used. The FTIR spectra results confirmed the PU octenylsuccination and also the presence of the BW in the composite films. The scanning electron microscopy (SEM) micrographs showed that the PU modification with OSA powerfully retarded the coalescence of BW droplets in film casting process and led to their homogeneity in the dried films. Also, the findings indicated that the water-proof properties including water solubility, water vapor permeability and water contact angle in the PU films were improved by the PU modification and BW incorporation. In addition, the obtained data showed that the octenylsuccination of PU had a negative effect on the mechanical properties of the produced films, while BW incorporation into PU-OSA films led to resolve this drawback.

Octenyl succinylation of kefiran: Preparation, characterization and functional properties.

In this study, kefiran was esterified with octenyl succinic anhydride (OSA). The esterification reaction variables including pH (8.5), kefiran concentration (5% (w/w)), OSA concentration (12% (w/w)), temperature (~38 °C) and reaction time (~80 min) were found as optimum points to achieve the maximum degree of substitution (DS) (0.041 ± 0.002). Kefiran-OSA samples with DS of 0.021 (FDA suggested DS) and 0.041 (maximum DS) were prepared and compared with unmodified kefiran in all experiments. FTIR and 1H NMR spectroscopies proved the grafting of OSA on kefiran structure. XRD analysis revealed that with increase in DS, the physical state of kefiran to be more amorphous. In addition, the esterification modification led to a decrease in the degradation temperature and an increase in the apparent viscosity based on the obtained data from thermal analysis and viscosity measurement. The results of the foaming and emulsifying properties confirmed the improvement in surface properties of the modified kefiran. The frequency sweep test illustrated that with an increase in DS, the viscoelastic behavior of the kefiran cryogels to be more viscous. It can finally be stated that the modification with OSA was a high potential strategy to extend the industrial applications of the kefiran.

Chemical modification of pullulan exopolysaccharide by octenyl succinic anhydride: Optimization, physicochemical, structural and functional properties.

Pullulan (PU) is an exo-polysaccharide used in the food and pharmaceutical industries. However, the use of PU in different industries is limited due to its highly hydrophilic nature and consequently weakness in surface properties which can be remedied by its chemical modification with octenyl succinic anhydride (OSA). For this purpose, PU modification with OSA was optimized and the results showed that the maximum degree of substitution (0.061 ± 0.003) was obtained under pH of 9.0, pullulan concentration of 40% (w/w), temperature of ~40.90 °C, reaction time of ~101.21 min and OSA concentration of 14.96% (w/w). Also, the grafting of OSA on pullulan structure was confirmed by FTIR, 1H NMR and zeta-potential analyzes. Although this modification had no significant effect on the amorphousity of pullulan, it led to an increase in viscosity and a decrease in decomposition temperature and surface tension. Improvement of emulsifying properties of PU-OSA sample was proved by the evaluation of emulsifying capacity of un- and modified samples and also, zeta-potential, particle size and viscosity of the prepared emulsions. In line with surface characteristic results, an increase in foam capacity of modified samples was observed with decreasing the interfacial tension.

Extraction, chemical composition, rheological behavior, antioxidant activity and functional properties of Cordia myxa mucilage.

This paper aims to investigate chemical composition, rheological behavior, antioxidant activity and functional properties of Cordia myxa mucilage (CMM). Response surface methodology (RSM) demonstrated that optimum conditions for CMM extraction were as follow: ultrasound power of 99.37 W, extraction temperature of 88.05 °C and solid to water ratio of 16.25 w/w. CMM had, on average, 77.51% carbohydrate, 5.86% total ash, 8.90% protein, 6.90% moisture, and 1.00% fat. Due to a high level of nutrients, CMM can be suggested as a value added by-product in food and pharmaceutical systems. CMM is a low molecular weight polysaccharide containing three fractions with various molecular weights. FT-IR spectrum illustrated that this polymer had all typical bands and peaks characteristics of polysaccharides. Based on steady shear measurements, CMM can be introduced as a new source of hydrocolloid with high-temperature stability. CMM had the desirable antiradical capacity, water solubility and water/oil holding capacity.

Design and fabrication of pectin-coated nanoliposomal delivery systems for a bioactive polyphenolic: Phloridzin.

Nanostructured colloidal delivery systems comprising of pectin-coated nanoliposomes (pectonanoliposomes) were developed as carriers for a bioactive polyphenolic compound (phloridzin). Phloridzin-loaded nanoliposomes were fabricated using a heating-stirring-sonication method, and coated with low methoxyl pectin using an electrostatic deposition approach. Dynamic light scattering, micro-electrophoresis, atomic force microscopy, and UV-Visible spectroscopy were used to investigate the impact of system composition on the size, charge, morphology and stability as well as immobilization, adsorption and encapsulation efficiencies of the pectonanoliposomes. Response surface methodology was used to optimize the composition of the pectonanoliposomes based on particle size and charge characteristics. Linear, quadratic and interaction effects of 1,2-dioleoyl-3-trimethyl ammonium propane/lecithin, phloridzin/lecithin and pectin/liposome ratios significantly influenced the mean hydrodynamic diameter and/or surface charge of pectonanoliposomes. Second-order polynomial regression models were generated for intensity-weighted particle size and zeta potential of the designed carriers. Topographic and phase contrast images showed that pectonanoliposomes exhibited a range of different morphologies. Coating the nanoliposomes with pectin improved their immobilization and encapsulation efficiencies as well as physical storage stability. Cationic pectonanoliposomes were superior to plain systems regarding long-term stability. Our results suggest that pectonanoliposomes may be suitable delivery systems for polyphenolic nutraceuticals, such as phloridizin, in functional food and pharmaceutical applications.

Complex coacervation for the development of composite edible films based on LM pectin and sodium caseinate.

Coacervation between sodium caseinate (CAS) and low methoxyl pectin (LMP) at pH 3 was investigated as a function of protein/polysaccharide ratio. The highest amount of complex coacervates was formed at a CAS/LMP ratio of 2 at which the ζ-potential value was zero and the turbidity reached its highest value. Then, the properties of films based on these complex coacervates were studied. Coacervation resulted in decreasing water content and water sorption of films as the protein concentration increased. The mechanical properties of films were highly influenced by the formation of electrostatic complexes. The highest values of Young's modulus (182.97± 6.48MPa) and tensile strength (15.64±1.74MPa) with a slight increase of elongation at break (9.35±0.10%) were obtained for films prepared at a CAS/LMP ratio equal to 0.05. These findings show that interactions between LMP and CAS can be used to develop innovative packaging containing active molecules.

Optimization of microwave assisted extraction of pectin from sour orange peel and its physicochemical properties.

Microwave assisted extraction technique was used to extract pectin from sour orange peel. Box-Behnken design was used to study the effect of irradiation time, microwave power and pH on the yield and degree of esterification (DE) of pectin. The results showed that the optimum conditions for the highest yield of pectin (29.1%) were obtained at pH of 1.50, microwave power of 700W, and irradiation time of 3min. DE values of pectin ranged from 1.7% to 37.5%, indicating that the obtained pectin was low in methoxyl. Under optimal conditions, the galacturonic acid content and emulsifying activity were 71.0±0.8% and 40.7%, respectively. In addition, the emulsion stability value ranged from 72.1% to 83.4%. Viscosity measurement revealed that the solutions of pectin at low concentrations showed nearly Newtonian flow behavior, and as the concentration increased, pseudoplastic flow became dominant.

Aqueous extraction of pectin from sour orange peel and its preliminary physicochemical properties.

Sour orange peel, a by-product of the fruit juice industry, was used as a source of pectin. The effects of temperature (75-95°C), time (30-90 min), and liquid-solid ratio (20-40, v/w) were investigated on yield, methoxylation degree (DE), and galacturonic acid content using a Box-Behnken design and response surface methodology. The highest extraction yield (17.95 ± 0.3%) was obtained at temperature of 95°C, time of 90 min, and liquid-solid ratio of 25 (v/w). The DE values for the pectin ranged from 17% to 30.5%, indicating that the pectin was low in methoxyle. The emulsifying activity of pectin extracted under optimal conditions was 45%. The emulsions were 86.6% stable at 4°C and 71.4% at 23°C after 30 days of storage. The pectin exhibited Newtonian flow at low concentrations (≤ 1.0%, w/v); as the concentration increased, pseudoplastic flow became dominant.

Proteolytic and ACE-inhibitory activities of probiotic yogurt containing non-viable bacteria as affected by different levels of fat, inulin and starter culture.

In this study, the effects of fat (0.5 %, 3.2 % and 5.0 %), inulin (0.0 and 1.0 %) and starter culture (0.0 %, 0.5 %, 1.0 % and 1.5 %) on the angiotensin converting enzyme (ACE)-inhibitory activity of probiotic yogurt containing non-viable bacteria were assessed. Proteolytic activities of bacteria were also investigated. Yogurts were prepared either using a sole yogurt commercial culture including Streptococcus thermophilus and Lactobacillus delbrueckii subs. bulgaricus or bifidobacterium animalis BB-12 and Lactobacillus acidophilus La5 in addition to yogurt culture. Relative degrees of proteolysis were found to be considerably higher in yogurt samples than UHT milk as the control. Both regular and probiotic yogurts showed considerable ACE-inhibitory activities. Results showed that degree of proteolysis was not influenced by different fat contents, while was increased by high concentration of starter culture (1.5 % w/w) and reduced by inulin (1 % w/w). ACE-inhibitory activities of yogurt were also negatively affected by the presence of inulin and high levels of fat (5 % w/w). Moreover, yogurt containing probiotic bacteria showed higher inhibitory against ACE in comparison to the yogurt prepared with non-probiotic strains.

Characterization of edible emulsified films with low affinity to water based on kefiran and oleic acid.

New edible composite films based on kefiran and oleic acid (OA) at the ratio of 15, 25, and 35% (w/w) were prepared using emulsification with the aim of improving their water vapour barrier and mechanical properties. Film-forming solutions were characterized in terms of rheological properties and particle-size distribution. The impact of the incorporation of OA into the film matrix was studied by investigating the physical, mechanical, and thermal properties of the films. The water vapour permeability (WVP) of the emulsified films was reduced by approximately 33% by adding OA. The mechanical properties of kefiran films were also affected by adding OA: tensile strength was diminished, and elongation increased considerably. Differential scanning calorimetry showed that the glass transition temperature (T(g)) of the kefiran film was -16°C and was not considerably affected by adding OA. Therefore, OA could be incorporated into these films for some food-technology applications that need a low affinity toward water.