Valorization of Parmentiera aculeata juice in growth of probiotics in submerged culture and their postbiotic production: a first approach to healthy foods.

Nowadays, functional foods are greatly accepted by consumers because they improve health and are new sources for substrates to be explored. In this sense, Parmentiera aculeata, a plant distributed in Mexico with beneficial effects on health, has not been chemically explored. In this work, P. aculeata juice was used as carbon source to promote the growth of two probiotic Lactobacillus strains during submerged fermentation. Taguchi's methodology with orthogonal array L9 was applied for culture conditions optimization. pH, agitation, and inoculum concentration variables, each with three levels, were evaluated and the best treatment was validated through a kinetic culture monitoring some postbiotics traits. We observed an increase in 1.76-times in cellular concentration of L. plantarum 14917, and the main produced postbiotics were short-chain fatty acids such as succinic, formic, acetic, propionic, and lactic acids, which are associated with the probiotic metabolism and are important for human health. In the best of our knowledge, this study is the first to describe the valorization of P. aculeata juice as substrate for growth of probiotic strains and future studies are required to gain further applications in functional food production.

Nutraceutical Quality and Soluble Solids of Cucumis melo Developed in Vermicompost-River Sand Mixtures, Under Shade Mesh Conditions.

<b>Background and Objective:</b> There is ample evidence that the consumption of fruits and vegetables, with a high content of secondary metabolites, favours better human health. In the same sense, the application of organic fertilizers has favoured the content of phenolic compounds and a greater antioxidant capacity in various crops. Factoring that the application of Vermicompost (VC) increases the nutritional quality of plants. This research determined the content of soluble solids, biochemical components and the antioxidant capacity of the melon fruits (<i>Cucumis melo</i> L.) developed under shade net conditions with VC as a source of fertilization. <b>Materials and Methods:</b> During the 2020 spring-summer season, a hybrid melon Honeydew type was grown under five mixtures of VC: River sand (RS), with ratios 0:1, 1:1, 1:2, 1:3 and 1:4. Nutrient Steiner solution was applied only in the first mixture (control) while VC was used as an organic nutrient for all other mixtures. The five formulated mixtures, with five replications, were randomly distributed. The total phenolic content, total flavonoids, antioxidant capacity and the total soluble solids of the melon fruit were determined. Data obtained were statistically analyzed by analysis of variance and means were compared by Tukey 0.05 test. <b>Results:</b> The ANOVA indicates that no statistical differences were registered for any of the variables under study, however, the levels of the parameters were high. <b>Conclusion:</b> VC treatment of melon fruit is proven to be a promising source of nutrients to plants increasing their natural antioxidants and content of soluble solids.

The secondary metabolites from Beauveria bassiana PQ2 inhibit the growth and spore germination of Gibberella moniliformis LIA.

Fungal secondary metabolites with antimicrobial properties are used for biological pest control. Their production is influenced by several factors as environment, host, and culture conditions. In the present work, the secondary metabolites from fermented extracts of Beauveria bassiana PQ2 were tested as antifungal agents against Gibberella moniliformis LIA. The L18 (21 × 37) orthogonal array from Taguchi methodology was used to assess 8 parameters (pH, agitation, sucrose, yeast extract, KH2PO4, MgSO4, NH4NO3, and CaCl2) in B. bassiana PQ2 submerged fermentation. The ability of the fermented extracts to slow down the growth rate of G. moniliformis LIA was evaluated. The results from 18 trials were analyzed by Statistica 7 software by evaluating the signal-to-noise ratio (S/N) to find the lower-the-better condition. Optimal culture conditions were pH, 5; agitation, 250 rpm; sucrose, 37.5 g/L-1; yeast extract, 10 g/L-1; KH2PO4, 0.8 g/L-1; MgSO4, 1.2 g/L-1; NH4NO3, 0.1 g/L-1; and CaCl2, 0.4 g/L-1, being the agitation at the highest level the most significant factor. The optimal conditions were validated in a sparged bottle bioreactor resulting in a higher S/N value (12.48) compared to the estimate. The extract obtained has the capacity to inhibit the germination of G. moniliformis spores at 24 h. HPLC-ESI-MS2 allowed to identify the water-soluble red pigment as oosporein (m/z 304.9). The secondary metabolites from B. bassiana PQ2 are a suitable alternative to control the growth and sporulation of G. moniliformis.

Antioxidant and antibacterial activities of a starch film with bioextracts microencapsulated from cactus fruits (Opuntia oligacantha).

The use of unconventional sources is very relevant in the food area. In the present study the development of active films with the addition of bioextract (BE) or microencapsulated bioextract (MBE) from xoconostle (Opuntia oligacantha) on chayotextle starch was investigated. The film formulations were: 4 g of chayotextle starch, 2 g of glycerol and 180 g of water, three films with BE added (0.4, 0.8 and 1.2 g) and three films with MBE added (0.4, 0.8 and 1.2 g). Total phenols, total flavonoids, antioxidant activity (ABTS and DPPH), Salmonella typhimurium inhibition, color and mechanical properties of the films were analyzed. The film with 1.2 g of MBE showed high concentration of total phenols (54.12 ± 0.77 mg EAG/100 g), total flavonoids (16.65 ± 0.10 mg QE/100 g) and antioxidant activity (29.11 ± 0.48 and 41.42 ± 1.81 mg EAA for ABTS and DPPH respectively). The addition of bioextract from xoconostle is an option for the development of active films with antioxidant properties.

Influence of Bioactive Compounds Incorporated in a Nanoemulsion as Coating on Avocado Fruits (Persea americana) during Postharvest Storage: Antioxidant Activity, Physicochemical Changes and Structural Evaluation.

The objective of the present study was to determine the effect of the application of a nanoemulsion made of orange essential oil and Opuntia oligacantha extract on avocado quality during postharvest. The nanoemulsion was applied as a coating in whole fruits, and the following treatments were assessed: concentrated nanoemulsion (CN), 50% nanoemulsion (N50), 25% nanoemulsion (N25) and control (C). Weight loss, firmness, polyphenol oxidase (PPO) activity, total soluble solids, pH, external and internal colour, total phenols, total flavonoids, antioxidant activity by 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), while the structural evaluation of the epicarp was assessed through histological cuts. Significant differences were found (p < 0.05) among the treatments in all the response variables. The best results were with the N50 and N25 treatments for firmness and weight loss, finding that the activity of the PPO was diminished, and a delay in the darkening was observed in the coated fruits. Furthermore, the nanoemulsion treatments maintained the total phenol and total flavonoid contents and potentiated antioxidant activity at 60 days. This histological study showed that the nanoemulsion has a delaying effect on the maturation of the epicarp. The results indicate that using this nanoemulsion as a coating is an effective alternative to improve the postharvest life of avocado.

Antibacterial activity and phenolic content of propolis extracts obtained by different extraction methods

Introduction: The data available regarding the chemical composition and procedures for the extraction of the propolis are currently inconclusive. In this study the chemical groups present in the extracts of a propolis mixture obtained by different methods were identified. Additionally, their content of polyphenols and flavonoids was determined, and antioxidant and antibacterial activity was studied. Method: The extracts were obtained by maceration and for the ultrasonic and microwave method. Phenolic and flavonoid compounds, as well as the measurement of antioxidant activity, were quantified by spectrophotometric methods. The antibacterial activity was studied from the inhibitory effect of each extract against Escherichia coli, Salmonella typhi, Staphylococcus aureus and Proteus mirabilis, and by the percentage of activity and the Index of Bacterial Susceptibility (IBS). Results: The phytochemical screening evidenced the presence of abundant compounds with important biological activity. It was found a significant difference (p<0.05) in the antioxidant and antimicrobial activity of the extracts of propolis obtained by different methods. Conclusion: The presence of chemical groups of bioactive compounds and their antioxidant and antibacterial activity justifies the use of these extracts in traditional medicine.

Introducción: Los datos disponibles sobre la composición química y los procedimientos para la extracción del propóleo son actualmente inconclusos. En este estudio se identificaron los grupos químicos presentes en los extractos de una mezcla de propóleos obtenidos por diferentes métodos. Además, se determinó su contenido de polifenoles y flavonoides y se estudió su actividad antioxidante y antibacteriana. Método: Los extractos se obtuvieron por maceración, por el método ultrasónico y mediante microondas. Los compuestos fenólicos y flavonoides, así como la medición de la actividad antioxidante, se cuantificaron por métodos espectrofotométricos. La actividad antibacteriana se estudió a partir del efecto inhibitorio de cada extracto contra Escherichia coli, Salmonella typhi, Staphylococcus aureus y Proteus mirabilis, así como por el porcentaje de actividad y el Índice de Susceptibilidad Bacteriana (IBS). Resultados: El tamiz fitoquímico evidenció la presencia de abundantes fitoquímicos biológicamente activos. Se encontró una diferencia significativa (p<0.05) en la actividad antioxidante y antimicrobiana de los extractos de propóleos obtenidos por diferentes métodos. Conclusión: La presencia de grupos químicos de compuestos bioactivos y su actividad antioxidante y antibacteriana justifica el uso de estos extractos en la medicina tradicional.