Proximate Composition and Seed Lipid Components of Sorghum Cultivars from Argentina

Seeds of 11 sorghum cultivars ( Sorghum bicolor ) from Argentina were analysed for proximate composition, fatty acids and sterols. Oil, protein, carbohydrate and ash contents varied between 41 and 66 g kg⁻¹, 111 and 156 g kg⁻¹, 670 and 730 g kg⁻¹ and 13·8 and 20·6 g kg⁻¹ of dry matter, respectively. Fatty acid profiles revealed that the major acids were palmitic (15·1–24·8%), oleic (29·9–41·8%) and linoleic (35·9–51·3%). Unsaponifiable matter was examined for sterols. Sitosterol was the prominent component in all cultivars (43·8–57·9%), followed by campesterol (18·7–29·1%) and stigmasterol (12·4–20·5%).     

Application of full-factorial design for optimization of the moisture determination in wheat flour using infrared scales

We studied the parameters that may affect the analysis of the moisture content in wheat flour using infrared scales. The parameters were studied by one-factor at a time methodology and then, by full-factorial design (2³). The best condition using infrared scales occurred at 120 °C, with a sample weight of 1.5 g and an exposure time to infrared radiation of 6 min. We observed the interaction effect between the three factors studied. The analysis time was 60 times lower than classical method. The optimized method for determination of the moisture content in wheat flour using infrared scales was validated to range between 9 and 17 %.     

Physical and nutritional properties of extruded products based on whole grain with the addition of wild legumes (Vicia lutea subsp. lutea var. hirta and Vicia sativa subsp. sativa)

Flour blends based on whole corn and rice with two added wild legumes at 15% level of cereal replacement were extruded to produce whole grain snacks. Extrusion temperature was 175 °C, and the moisture content was adjusted to 14%. The extruded products were evaluated for their physical, chemical and nutritional properties. Results showed that the addition of legumes produces a decrease in expansion in rice‐containing samples and an increase in solubility in corn‐containing samples. With only 15% of legume added to cereal, a significant increase in protein content and quality was obtained. An increase in fibre, polyphenol, iron and zinc content was also obtained. Protein digestibility was in the range of 81.8–85.3%. Mineral availability ranged from 6.4 to 16.3% for iron and 10–16.3% for zinc. The performance of each mixture during extrusion and the physical properties of the extruded products were considered to be similar to those expected for snack‐type products and described in the literature.     

Ethylene production,respiration and gas exchange modelling in modified atmosphere packaging for banana fruits

A mathematical model was developed from experimental measurements to describe the evolution of the O₂, CO₂ and ethylene in a modified atmosphere packaging system for Cavendish bananas. The respiration and ethylene production in the fruits were experimentally obtained from a closed system method and then represented by Michaelis–Menten equations of enzyme kinetics. The gas transfer through the packaging was described by a Fick's diffusion equation, and the temperature dependence was represented based on the Arrhenius law. The model was validated by packaging the fruit in perforated bags of polypropylene and low density polyethylene at 12 °C for a period of 8 days. With the developed model it was possible to satisfactorily describe the experimental evolution of the gas content in the headspace of the packages, obtaining coefficients of determination (R²) of 0.93 for the O₂ levels, 0.90–0.91 for the CO₂ levels, and 0.89–0.93 for the ethylene levels.     

Food protozoa safety assessment and risk in school restaurants in Armenia,Colombia

This work assessed the risk of protozoa in 10 school restaurants in Armenia (Quindío, Colombia) by analyzing the presence of Cryptosporidium spp, Giardia duodenalis, Blastocystis, and Cyclospora cayetanensis DNA in the food, water, and living and inert surfaces of school restaurants and in stools of children who ate at these restaurants. Of the 213 food, water, and surface samples, 6.6% were positive using PCR to test DNA for Blastocystis; 3.8% for Cryptosporidium spp; 0.9% for G. duodenalis; and 0% for C. cayetanensis. In 187 stool samples analyzed via microscopy from children who attended the restaurants, 40 (21.4%) were positive for Blastocystis and 21 (11.2%) were positive for Giardia spp. Via PCR, 20 (10.7%) were positive for Cryptosporidium and 0 (0%) for C. cayetanensis. A higher positivity in children's stools for Blastocystis spp was correlated with lower compliance in property conditions and for higher positivity of Giardia spp in children's stool was related to lower knowledge by food manipulators. Inspection scores can identify restaurants with higher risk for protozoa infection.     

Changes in optical properties caused by UV-irradiation of aquatic humic substances from the amazon river basin: seasonal variability evaluation

Aquatic humic substances (AHS) isolated from two characteristic seasons of the Negro river, winter and summer corresponding to floody and dry periods, were structurally characterized by 13C nuclear magnetic ressonance. Subsequently, AHS aqueous solutions were irradiated with a polychromatic lamp (290-475 nm) and monitored by its total organic carbon (TOC) content, ultraviolet-visible (UV-vis) absorbance, fluorescence, and Fourier transformed infrared spectroscopy (FTIR). As a result, a photobleaching up to 80% after irradiation of 48 h was observed. Conformational rearrangements and formation of low molecular complexity structures were formed during the irradiation, as deduced from the pH decrement and the fluorescence shifting to lower wavelengths. Additionally a significant mineralization with the formation of CO2, CO, and inorganic carbon compounds was registered, as assumed by TOC losses of up to 70%. The differences in photodegradation between samples expressed by photobleaching efficiency were enhanced in the summer sample and related to its elevated aromatic content. Aromatic structures are assumed to have high autosensitization capacity effects mediated by the free radical generation from quinone and phenolic moieties.     

Antioxidant and cardioprotective activities of phenolic extracts from fruits of Chilean blackberry Aristotelia chilensis (Elaeocarpaceae), Maqui

The methanol extract from mature fruits of Aristotelia chilensis (Mol) Stuntz (Elaeocarpaceae) showed antioxidant activities and cardioprotective effects on acute ischemia/reperfusion performed in rat heart in vivo. This extract protected animals from heart damage by the incidence of reperfusion dysrythmias, and the no-recovery of sinus rhythm. On the other hand, the MeOH extract of the fruit was able to prevent these harmful events in the animal’s heart by diminishing lipid oxidation and reducing the concentration of thiobarbituric acid reactive substances (TBARS), a lipid peroxidation index. In addition, MeOH extract of A. chilensis was evaluated for DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, crocin radical scavenging, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), an estimation of lipid peroxidation in liposomes through the inhibition of formation of TBARS. MeOH extract was found to have IC₅₀ of 1.62 ppm against DPPH and 2.51 ppm against TBARS, compared with the juice, whose IC₅₀ was 12.1 ppm and 9.58 ppm against DPPH and TBARS formation, respectively. Antioxidant activities of MeOH extract were strongly correlated with total polyphenol content. Consistent with this finding, MeOH had the greatest ORAC and FRAP values as percentage of activity. These results show that these fruits could be useful as antioxidant, cardioprotective and nutraceutical sources.     

Functional properties and health benefits of bioactive peptides derived from Spirulina: A review

Bioactive peptides represent specific sequences of amino acids that have biological activity with several health effects and potential applications, which can be obtained from diverse protein sources. Spirulina, the cyanobacterium known for its high protein content and therapeutic properties, has been investigated as a potential source of bioactive peptides. Some bioactive peptides derived from Spirulina are under study for their ability to offer specific health benefits, such as antimicrobial, antiallergic, antihypertensive, antitumor, and immunomodulatory properties. Bioactive peptide fractions from Spirulina biomass can be obtained through a series of operations, including cell lysis and protein extraction, enzymatic hydrolysis, potential bioactivity screening, fractionation, and purification. Potentially, Spirulina-derived peptide fractions can be applied as nutraceutical ingredients in foods and pharmaceuticals. This article reviews the functional properties and health benefits of bioactive peptides from Spirulina, and presents potential mechanisms by which bioactive components can be exploited in the development of novel foods with special health claims. In addition, this article describes recent developments in proteomics, bioactivity screening methods, and opportunities for designing future peptide-based foods.     

Assessment of production efficiency,physicochemical properties and storage stability of spray‐dried chlorophyllide,a natural food colourant,using gum Arabic,maltodextrin and soy protein isolate‐based carrier systems

The aim of this research was to study spray drying as potential action to protect chlorophyllide from environmental conditions for shelf‐life extension and characterisation of the powders. Six formulations were prepared with 7.5 and 10 g of carrier agents [gum Arabic (GA), maltodextrin (MA) and soybean protein isolate (SPI)]/100 mL of chlorophyllide solutions. The powders were evaluated for morphological characteristics (SEM), particle size, water activity, moisture, density, hygroscopicity, cold water solubility, sorption isotherms, colour and stability, during 90 days. All the powders were highly soluble, with solubility values around 97%. A significant lower hygroscopicity was observed for GA powders, whilst the lower X_m values obtained by GAB equation fitting of the sorption isotherms was observed for the 7.5 g MA/100 mL samples. All formulations, but the 1 (7.5 g SPI/100 mL of chlorophyllide), provided excellent stability to the chlorophyllide during 90 days of storage even at room temperature.