Global Research Trends on the Utilization of Nopal (Opuntia Sp) Cladodes as a Functional Ingredient for Industrial Use.

Although nopal cladodes are a valuable bioactive compound source, they have historically been underused. This review draws a parallel between quantitative and qualitative data from the most outstanding scientific research concerning nopal cladodes in the last five years by implementing a bibliometric analysis. Italy, Mexico, Brazil, and Morocco accounted for approximately 55% of the 111 articles selected for this review. Nopal cladodes are a great source of nourishing ingredients such as mucilage, pectin, insoluble fibers, minerals, ascorbic acid, and bioactive compounds such as carotenoids (e.g., ß-carotene, lutein, and cryptoxanthin), flavonoids (e.g., isorhamnetin, quercetin, rutin, and catechin), phytosterols (e.g., ß-sitosterol and ß-campesterol). Additionally, they offer technological benefits as a food ingredient, allied to good sensory acceptability. The findings suggest that medium-aged cladodes (20 days) have the highest concentration of soluble fiber, protein, and bioactive compounds, rendering them the optimal maturity stage for consumption and processing. Therefore, nopal cladodes can be exploited for several industries, including biotechnology, cosmetics, and pharmaceuticals, and they have attracted attention as a promising ingredient for the food industry in the concept of the next generation of innovative and functional vegetable foods.

Evaluating how avocado residue addition affects the properties of cassava starch-based foam trays.

Avocado seed (AS) is an interesting residue for biopackaging because it has high starch content (41 %). We have prepared composite foam trays based on cassava starch containing different AS concentrations (0, 5, 10 and 15 % w/w) by thermopressing. Composite foam trays with AS were colorful because this residue contains phenolic compounds. The composite foam trays 10AS and 15AS were thicker (2.1-2.3 mm) and denser (0.8-0.9 g/cm3), but less porous (25.6-35.2 %) than cassava starch foam (Control). High AS concentrations yielded composite foam tray less puncture resistant (∼40.4 N) and less flexible (0.7-0.9 %), but with tensile strength values (2.1 MPa) almost similar to the Control. The composite foam trays were less hydrophilic and more water resistant than control due to the presence of protein, lipid, and fibers and starch with more amylose content in AS. High AS concentration in composite foam tray decreases the temperature of thermal decomposition peak corresponding to starch. At temperatures >320 °C the foam trays with AS were more resistant to the thermal degradation due to the presence of fibers in AS. High AS concentrations delayed the degradation time of the composite foam trays by 15 days.

Structural modification of fiber and starch in turmeric residue by chemical and mechanical treatment for production of biodegradable films.

The dye extraction from turmeric rhizomes (Curcuma longa L.) is generated a residue with high starch content that in nature does not form film. Therefore, we decided evaluate how mechanical treatment (ball or cryogenic mill) and chemical treatment with alkali (NaOH 2.5% (1, 4, or 8 h) and bleaching with NaClO or H2O2 at 25 or 45 °C affect the chemical structure of the starch and fibers in turmeric residue, and its filmogenic capacity. Ball milling decreased the turmeric residue particle size more effectively favoring the chemical procedures. Only two types of chemical treatment consisting in alkaline treatment for 4 h and bleaching with NaClO and H2O2, respectively, for 4 h, at 25 °C yielded turmeric residues with filmogenic capacity. The chemical treatments oxidized the starch granules causing to lose their crystal structure as verified by DRX, and removed amorphous fibers such as lignin and hemicellulose increasing cellulose content in turmeric residue. FTIR analyses also revealed that the starch granules were oxidized. As bleaching agent, NaClO caused greater starch oxidation (the highest carboxyl and carbonyl groups contents) affording films with the best mechanical and functional properties. Although chemical treatment reduced the turmeric residue phenolic compounds, the films still presented antioxidant activity.

Biodegradable foam tray based on starches isolated from different Peruvian species.

Starch was isolated from three Andean-native crops - arracacha (Arracacia xanthorrhiza), oca (Oxalis tuberosa), and sweet potato (Ipomoea batatas) - for use as a raw material for the production of foam trays. The starches were characterized in their proximal composition, crystallinity, microstructure and thermal properties. The sweet potato starch showed the highest amylose content (42.65%) and the lowest protein content (0.30%). The oca starch granules were larger (10-30 µm) than sweet potato and arracacha starch. The highest crystallinity of sweet potato starch caused larger values of onset temperature (To), peak temperature (Tp), conclusion temperature (Tc) (67.64 °C, 72.83 °C, and 81.20 °C, respectively) than arracacha and oca starch. The novel foam trays showed good appearance, adequate expansion, and low density; however, all foam trays showed a water absorption capacity >50%, which was related to their porosity and low density. Also, sweet potato and oca starch trays showed high tensile strength (0.67 and 0.65 MPa, respectively) compared with arracacha starch trays (0.52 MPa).

Soybean straw nanocellulose produced by enzymatic or acid treatment as a reinforcing filler in soy protein isolate films.

This work is a comparative study of the application of mercerized soybean straw (MSS) and nanocellulose produced by acid (CNCs) or enzymatic hydrolysis (CNFs) as reinforcing fillers in soy protein isolate (SPI) films. CNCs presented average dimensions of about 10 nm-thick and 300 nm-long with a crystallinity index of 57%, whereas CNFs have similar diameters, though with greater lengths (>1 µm), lower crystallinity index (50%) and greater thermal stability. Incorporation of 5% of CNCs and CNFs (g/100 g of SPI) improved the SPI film tensile strength by 38 and 48% respectively, and decreased the SPI film elongation at break when compared to control films. The SPI-CNC films showed the lowest values for solubility, probably due to their higher crystallinity (63%). On the other hand, the water vapor permeability was solely reduced with CNF addition, which can be attributed to their higher aspect ratio (length/diameter) and a better incorporation into the protein matrix.

Chemical treatment and characterization of soybean straw and soybean protein isolate/straw composite films.

This work investigated changes in the chemical composition and structure of soybean straw (SS) treated with alkali (NaOH 5% and 17.5%) and bleached with hydrogen peroxide (H2O2) or sodium hypochlorite (NaOCl). Removal of the amorphous constituents increased the degree of crystallinity and the content of cellulose fibers particularly after reaction with high concentrations of alkali. Treatment with NaOH 17.5% contributed to the allomorph transition from cellulose I to II regardless of the bleaching agent, but H2O2 as bleaching agent promoted more effective delignification. This work also evaluated the potential use of treated and non-treated SS as reinforcement filler in soy protein isolate film (SPI). Films added with treated SS presented higher mechanical resistance, lower elongation at break, and lower solubility in water. Addition of non-treated SS did not affect the properties of the SPI film significantly. The low solubility and the reasonable water vapor permeability of the composite films make them suitable packaging materials for fresh fruit and vegetables.

Formation of carrageenan-CaCO3 bioactive membranes.

The high biocompatibility and resorbability of polymeric membranes have encouraged their use to manufacture medical devices. Here, we report on the preparation of membranes consisting of carrageenan, a naturally occurring sulfated polysaccharide that forms helical structures in the presence of calcium ions. We incorporated CaCO3 particles into the membranes to enhance their bioactivity and mechanical properties. Infrared spectroscopy and X-ray diffraction data confirmed CaCO3 incorporation into the polymeric matrix. We tested the bioactivity of the samples by immersing them in a solution that mimics the ionic composition and pH of the human body fluid. The hybrid membranes generated hydroxyapatite, as attested by X-ray diffraction data. Scanning electron and atomic force microscopies aided investigation of membrane topography before and after CaCO3 deposition. The wettability and surface free energy, evaluated by contact angle measures, increased in the presence of CaCO3 particles. These parameters are important for membrane implantation in the body. Moreover, membrane stiffness was up to 110% higher in the presence of the inorganic particles, as revealed by Young's modulus.

Potential of Amaranthus cruentus BRS Alegria in the production of flour, starch and protein concentrate: chemical, thermal and rheological characterization.

BACKGROUND: Amaranth is a little-known culture in Brazilian agriculture. Amaranthus cruentus BRS Alegria was the first cultivar recommended by Embrapa for the soil of the Brazilian scrubland. In order to evaluate the potential of this species in the production of flour, starch and protein concentrates, the latter products were obtained from A. cruentus BRS Alegria seeds, characterized and compared with the products obtained from the A. caudatus species cultivated in its soil of origin. RESULTS: The seeds of A. cruentus BRS Alegria furnished high-purity starch and flour with significant content of starch, proteins, and lipids. The starch and flour of this species presented higher gelatinization temperatures and formed stronger gels upon cooling compared with those obtained from the A. caudatus species. This is due to their greater amylose content and a difference in the composition of the more important fatty acids, such as stearic, oleic and linoleic acids, which indicates that they have greater heat stability. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and differential scanning calorimetry revealed the presence of albumins, globulins, glutelins and prolamins in the protein concentrate, which was obtained as a byproduct of starch production. CONCLUSION: Amaranthus cruentus BRS Alegria has potential application in the production of flour, starch and protein concentrates, with interesting characteristics for use as food ingredients.