Co-Microencapsulation of Sacha Inchi (Plukenetia huayllabambana) Oil with Natural Antioxidants Extracts

Sacha inchi (Plukenetia huayllabambana) oil was co-microencapsulated with natural antioxidant extracts (NAE), such as camu-camu (Myrciaria dubia (HBK) Mc Vaugh) fruit, Añil variety Andean potato (Solanum tuberosum andigenum, and elderberry fruit (Sambucus peruviana). Gum Arabic and the ternary combination of gum Arabic (GA) + maltodextrin (MD) + whey protein isolate (WPI) at different formulations were used as coating materials for the encapsulation process using spray-drying. The moisture content, particle size distribution and morphology, total phenolic content, antioxidant activity, fatty acid and sterol composition, oxidative stability, and shelf-life were evaluated. Co-microcapsules of sacha inchi (P. huayllabambana) oil with camu camu skin extract (CCSE) at 200 ppm encapsulated with GA + MD + WPI had the highest total polyphenol content (4239.80 µg GAE/g powder), antioxidant activity (12,454.00 µg trolox/g powder), omega-3 content (56.03%), β-sitosterol (62.5%), greater oxidative stability (Oxidation Onset temperature of 189 °C), higher shelf-life (3116 h), and smaller particle sizes (6.42 μm). This research enhances the knowledge to obtain microcapsules containing sacha inchi (P. huayllabambana) oil with natural antioxidant extracts that could be used for the development of functional foods. Further research is needed to study the potential interactions and their influence between the bioactive components of the microcapsules and the challenges that may occur during scale-up to industrial production.

Implications of miR166 and miR159 induction to the basal response mechanisms of an andigena potato (Solanum tuberosum subsp. andigena) to salinity stress, predicted from network models in Arabidopsis

MicroRNA (miRNA) mediated changes in gene expression by post-transcriptional modulation of major regulatory transcription factors is a potent mechanism for integrating growth and stress-related responses. Exotic plants including many traditional varieties of Andean potatoes (Solanum tuberosum subsp. andigena) are known for better adaptation to marginal environments. Stress physiological studies confirmed earlier reports on the salinity tolerance potentials of certain andigena cultivars. Guided by the hypothesis that certain miRNAs play important roles in growth modulation under suboptimal conditions, we identified and characterized salinity stress-responsive miRNA-target gene pairs in the andigena cultivar Sullu by parallel analysis of noncoding and coding RNA transcriptomes. Inverse relationships were established by the reverse co-expression between two salinity stress-regulated miRNAs (miR166, miR159) and their target transcriptional regulators HD-ZIP-Phabulosa/Phavulota and Myb101, respectively. Based on heterologous models in Arabidopsis, the miR166-HD-ZIP-Phabulosa/Phavulota network appears to be involved in modulating growth perhaps by mediating vegetative dormancy, with linkages to defense-related pathways. The miR159-Myb101 network may be important for the modulation of vegetative growth while also controlling stress-induced premature transition to reproductive phase. We postulate that the induction of miR166 and miR159 under salinity stress represents important network hubs for balancing gene expression required for basal growth adjustments.