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The aim of this study was to evaluate the effects of chitosan-tomato plant extract (C-TPE) edible coating (EC) applications on the physicochemical, microbiological, sensory and antioxidant capacity of chicken during storage. Edible coatings prepared with chitosan 1%, acetic acid 1%, glycerol and TPE (0.1 and 0.3%) were tested. The slices were submerged for 1 minute in different treatments (T1: C 1%; T2: C 1% + TPE 0.1%; T3: C 1% + TPE 0.3%; T4: control) and stored at 4 °C. At the end of the storage period, the treatments exhibited the greatest physicochemical and microbiological effects in the slices, reducing the microbial population relative to the control. The T2 treatment exhibited the highest antioxidant capacity, total phenolic content and overall acceptance. The results demonstrate that the application of C with the addition of a natural extract, such as those from the tomato plant, can be an alternative method for preserving chicken meat.

Crude extracts of collagenases from jumbo squid (Dosidicus gigas) hepatopancreas and sierra fish (Scomberomorus sierra) viscera were used to hydrolyse squid muscle collagen into peptides with inhibitory capacity over angiotensin I-converting enzyme (ACE) and ABTS free radicals [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)], as a measure of their antihypertensive potential and antioxidant activity, respectively. Proteins from 20 to 200 kDa were found in both enzyme extracts; however, in comparison to the jumbo squid extract (JSE), the extraction yield and specific activity of the enzymatic sierra fish extract (SFE) were ≈ 40% greater, suggesting the presence of enzymes with different collagenolytic activity. Moreover, the utilised collagen was obtained with a yield of 0.98 ± 0.09 g/100 g muscle from jumbo squid arms, which after an incubation with JSE and SFE generated peptides with different biological activity. However, the collagen hydrolysates from the enzymatic SFE contained a higher proportion of low-molecular-weight peptides than that obtained from JSE (15.2 and 7.9% of

Stenocereus thurberi is an endemic species in northwestern Mexico. It produces colorful fruits called pitayas that have an edible pulp. They have phytochemical compounds associated with biological activities. Ultrafiltration is a widely used method for the clarification of fruit juices and the recovery of phytochemicals. However, its effect has not been extensively studied in extracts. Therefore, the objective of this work is to study the effect of the ultrafiltration of pitaya extract (Stenocereus thurberi) on its phytochemical content, antioxidant capacity, and identification of phenolic compounds by UPLC-DAD-MS, providing greater knowledge about the pitaya. In this study, two extracts were analyzed, the unclarified extract (UE) and the clarified extract (CE). The antioxidant capacity was higher in the CE with 15.93 &plusmn, 0.42 mM TE/g, DPPH and 18.37 &plusmn, 0.016 mM TE/g, ABTS. The UPLC-MS analysis indicated the decrease in phenolic compounds in the CE and the presence of gallic acid and resorcinol, compounds that had not been identified in other species of Stenocereus spp. The correlation analysis indicated that all the phytochemicals present in the pitaya contribute significantly to the antioxidant capacity. The ultrafiltration process could be a viable option to improve the biological activity of the natural extracts.

Starch is composed of amylose and amylopectin and deposited as granules of different sizes and shapes with semi-crystalline and amorphous concentric layers that show the ‘maltese cross’. Starches from different sources show variable chemical composition as well as the structure of their components that are involved in thermal properties. Amylose, lipids, phosphorylated residues and long lateral chain amylopectin interact among them avoiding water uptake. In contrast, high amylopectin contents, especially with short lateral chains, allow hydration via hydrogen bonds to form gels with the tendency to retrogradation. Smaller starch granules have a larger superficial area, surface pores, and channels that enhance water uptake. High hydration increases the swelling, viscosity, and gelatinization ability of starch granules. The knowledge of those properties allows the selection of the most appropriate starch for a specific end use. This review discusses the relationship between the physicochemical composition of the starch and their rheological properties.

Chitosan films (CF) [1 and 2% w/v] alone and with cinnamaldehyde (CNE) [0.25, 0.5 and 1% v/v] were prepared using an emulsion method, and the obtained films were characterized in terms of water vapor permeability (WVP), water solubility and optical, mechanical and antioxidant properties. The incorporation of CNE at 1% (v/v) significantly decreased the water solubility of the film by approximately 4% for the 1 and 2% CF films, whereas the WVP increased (2.5–3.5 times). The incorporation of CNE (0.25 and 0.5%) into 2% CF significantly increased the tensile strength (TS) (62 and 34%, respectively) and the percent elongation (%E) values, 26, 30 and 52% for CF that contained 0.25, 0.5 and 1% CNE, respectively. The largest value of the elasticity modulus (EM) was observed for 2% CF with 0.25% CNE. All films exhibited a yellow appearance (b*), but the CNE content had a marked impact on the coloration of the films. The CNE recoveries of the CF films (1 and 2%) with 1% of CNE were high (43 and 67%). The antioxidant activities indicated that the incorporation of 1% CNE into CF films (1 and 2%) increased the antioxidant activity. The protective effects of the films with and without CNE on erythrocytes were very strong (36–72% hemolysis inhibition). These results suggest there are potential applications for CF-CNE films as active packaging for the preservation of food products.

The present study was accomplished to gain insights into the biochemical and kinetic properties of Rhyzopertha dominica’s α-amylase isoforms (named RdA70, RdA79, and RdA90) expressed in progenies reared in wheat varieties differing in α-amylase inhibitory activity. An inverse relationship was observed between the progenies’ amylase activity and the wheat inhibitory activity. Wheat samples with a high and low infestation (named HI-Borlaug and LI-Villa Juarez, respectively) were chosen to simplify the study. The progenies amylases were isolated by hydrophobic interaction chromatography, while the wheat samples were analyzed in α-amylase inhibitory activity by size exclusion chromatography. The isoforms RdA70 and RdA90 from LI-Villa Juarez progeny showed higher enzyme activities (73.8 and 43.4%, respectively) than those from HI-Borlaug. When the amylase isoforms were tested in susceptibility to inhibition by the inhibitory albumins, those from LI-Villa Juarez were more susceptible than those of the HI-Borlaug. Determination of the kinetic parameters revealed that RdA70 from the HI-Borlaug progeny showed 3.0-fold less starch affinity than that from the LI-Villa Juarez (Km of 12.3 ± 1.8 versus 4.0 ± 0.3). The rest of the α-amylases did not show the same pattern as RdA70 in the HI-Bourlag as that their starch affinity was further reduced (RdA79 Km = 23.1 ± 4.3, RdA90 Km = 17.1 ± 2.9). Estimation of IC50 values confirmed the high sensitivity of the three α-amylases of the LI-Villa Juarez progeny to wheat α-amylase inhibitors. The inhibitor constant Ki was the lowest for RdA70 in the LI-Villa Juarez progeny indicating the inhibitor’ tight binding to that isoenzyme. These results suggest that R. dominica uses RdA70 to bind large amounts of wheat α-amylase inhibitors than RdA79 and RdA90 as a physiological defense mechanism.

National Council of Science and Technology (CONACyT) [INFR-226208-2014, INFR-255791-2015]; CONACYT

Anemopsis californica, commonly known as yerba mansa, is an important medicinal plant that has traditionally been used to treat a variety of digestive, respiratory and skin ailments, and has been reported to possess anticancer properties. The increase in demand for this medicinal plant puts wild populations at risk due to over-harvesting; therefore, the development of alternatives such as in vitro propagation may help reduce this pressure on natural plant resources. The aim of this work was to develop protocols for the in vitropropagation of A. californica through axillary bud proliferation and somatic embryogenesis. Shoot bud multiplication was achieved using nodal explants from axenic seedlings, reaching the highest multiplication rate (on average 15 shoots per explant) when the culture medium was supplemented with 4 mg/L kinetin. Propagated shoots produced roots in medium containing 1 mg/L indole-3-butyric acid. Best induction of somatic embryogenesis (on average 19.75 embryos per explant) was obtained from leaf explants cultured on medium supplemented with 4 mg/L naphthalene acetic acid. These protocols may be used either for the commercial mass propagation of the species, studies on the production of secondary metabolites or as a basis for the development of genetic improvement strategies. Key words: Multiple shoot proliferation, regeneration of embryos, plant growth regulators,yerba mansa.