Melatonin Combined with Wax Treatment Enhances Tolerance to Chilling Injury in Red Bell Pepper.

Bell peppers (Capsicum annuum L.) are prone to chilling injury (CI) when stored at temperatures below 7 °C. Melatonin, a natural plant regulator, plays a critical role in defending against different pre- and post-harvest abiotic stresses, including those associated with cold storage. This study aimed to assess the effects of applying exogenous melatonin alone and in combination with a commercial wax on the CI tolerance, postharvest life, and potential biomarker search of red bell peppers. In the initial experiment, the effective melatonin concentration to reduce CI effects was determined. Peppers were sprayed with either distilled water (control) or a melatonin aqueous solution (M100 = 100 µM or M500 = 500 µM) and then stored for 33 d at 4 °C, followed by 2 d at 20 °C. The M500 treatment proved to be more effective in reducing fruit CI incidence (superficial scalds) and metabolic rate, while weight loss, softening, and color were comparable to the control. A second experiment assessed the potential synergistic effects of a combined melatonin and commercial wax treatment on pepper CI and quality. Fruits were sprayed with distilled water (control), melatonin (M500), commercial wax (Wax), or the combined treatment (Wax + M500) and stored for 28 d at 4 °C, followed by 2 d at 20 °C. The Wax + M500 was the most effective in significantly reducing the incidence of fruit CI symptoms and calyx fungal infection. Furthermore, this combined treatment enhanced fruit weight loss prevention compared with individual melatonin or wax treatment. Also, Wax + M500-treated peppers exhibited notable proline accumulation, indicative of a metabolic response counteracting the cold effects, resulting in better fruit stress acclimation. This treatment also preserved the peppers' color and antioxidant capacity. In summary, these findings highlight the suitability of applying a combined Wax + M500 treatment as a highly effective strategy to enhance the CI tolerance of peppers and extend their postharvest life.

Eggplant grafting on a cold-tolerant rootstock reduces fruit chilling susceptibility and improves antioxidant stability during storage.

BACKGROUND: Vegetable grafting has been increasingly evaluated to improve preharvest tolerance to biotic and abiotic stresses. However, very few studies have identified rootstock-scion combinations able to improve fruit shelf life and reduce the susceptibility to postharvest disorders. Herein, a purple eggplant scion (cv. Monarca) was grafted onto a cold-tolerant hybrid Solanum rootstock ('Java') and the changes in growth, quality, postharvest chilling tolerance, and antioxidant stability were evaluated. RESULTS: Eggplant grafting enhanced plant vigor and fruit growth rate, decreasing the time from set to harvest by 10-15%. Grafted eggplants had a thinner shape and lighter pulp color than the control. The rootstock-scion combination tested showed lower respiration (~60%), dry matter (~15-20%), and phenolic compounds contents (~15-20%) than eggplants from non-grafted plants. Grafting markedly improved fruit performance during postharvest storage. Remarkably, grafted eggplants showed much higher tolerance to chilling injury than the control did, evidenced by a reduction of surface scalds along with decreased softening and pulp browning. The trend in antioxidants found at harvest time was reversed after cold storage due to enhanced stability (20% and 100% for pulp and peel respectively) in fruit from grafted plants. CONCLUSION: Purple eggplant (cv. Monarca) grafting onto 'Java' hybrid rootstock modulated fruit growth, quality at harvest, and increased fruit chilling injury tolerance during storage. Grafting may be a bona fide strategy to induce phenotypic traits able to improve vegetable postharvest performance. © 2021 Society of Chemical Industry.

[Prevalence, awareness, treatment and control of cardiovascular risk factors in the Extremadura population (Spain). HERMEX study]. / Prevalencia, detección, tratamiento y grado de control de los factores de riesgo cardiovascular en la población de Extremadura (España). Estudio HERMEX.

OBJECTIVE: To estimate the prevalence, detection, treatment and degree of control of cardiovascular risk factors in Extremadura. DESIGN: Cross-sectional study. SETTING: Population study in Don Benito-Villanueva de la Serena health area (Badajoz). PARTICIPANTS: A random sample of the people between 25 and 79 years, who lived in this area, was selected. METHODS: History of cardiovascular risk factors and its treatment were obtained by questionnaire. Blood pressure and blood sample were obtained for all participants. We calculated the prevalence of each variable standardized for age and gender for the population of Extremadura. RESULTS: Of the 3521 eligible, 2833 (80.5%) participants were included, mean age 51.2 years, male 46.5%. Adjusted prevalence of current smoking in men: 40.5% (37.8-43.2), hypertension 39.5% (37.3-41.7), hypercholesterolemia, 37.9% (35.4-40.4), obesity 36.5% (33.9-39.1), diabetes 13.7% (12.1-15.4). Adjusted prevalence of hypercholesterolemia in women: 35,0% (32.9-37.2), hypertension 33,0% (31.3-34.7), obesity 30.7% (28.6-32.8), current smoking 26,6% (24.5-28.7), diabetes 12,0% (10.5-13.5). The detection level of each factor was above 70%, and the degree of control among those treated of 51, 62.3 and 74.7% for hypertension, diabetes and hypercholesterolemia, respectively. CONCLUSIONS: Extremadura's population is highly exposed to major cardiovascular risk factors, especially men. Smoking, obesity and diabetes stand in the national context as the most prevalent in our community.