In recent years, there has been great interest in the nutraceutical compounds of fruits from native Chilean plant species. In this context, fruits of Amomyrtus meli (Meli), Aristotelia chilensis (Maqui), Berberis microphylla (Calafate), Luma apiculata (Arrayán), Luma chequén (Chequén), and Ugni molinae (Murtilla) growing predominantly in Chilean forests have been studied. This chapter has compiled the existing information about antioxidant activity and antioxidant compound contents of the above mentioned fruit species and their association with the prevention of pathophysiological disorders in humans, such as inflammation, diabetes, and cardiovascular diseases. Results show that the antioxidant compounds of these species, particularly anthocyanins, decrease inflammation as well as the risk of diabetes and cardiovascular diseases. Therefore, consumption of these fruits is a good alternative for preventing cardiovascular and age-related diseases and pathophysiological disorders.

No abstract

Methyl jasmonate (MeJA) protective effect on photosynthetic performance and its association with antioxidants in two highbush blueberry (Vaccinium corymbosum L.) cultivars with contrasting aluminum (Al) resistance under Al toxicity was determined. Legacy (Al-resistant) and Bluegold (Al-sensitive) cultivars were subjected to control, MeJA, Al, and their combination (Al+ MeJA) for 0, 24, and 48 h under greenhouse conditions. Al concentration, oxidative damage (malondialdehyde (MDA) and H 2 O 2 concentrations), antioxidant activity (AA), superoxide dismutase (SOD) and catalase (CAT) activities, total polyphenols (TPP), chlorogenic acid, and in vivo photosynthetic performance were determined. The exposure to Al toxicity increased the Al concentration (up to 15-fold) and oxidative damage (up to 5.5-fold) compared to the control at 48 h, despite the antioxidant responses (SOD and CAT activities) were increased (up to 4-fold), mainly in the Al-sensitive cultivar at 48 h. Concomitantly, the photosynthetic performance was strongly reduced in the Al-sensitive cultivar (1.6-fold), while the Al-resistant cultivar was more stable during the experiment. However, when cultivars were exposed to Al+MeJA, the Al accumulation and oxidative damage strongly decreased (7-fold and 1.6-fold, respectively), increasing AA, SOD and CAT activities, and TPP in both cultivars during the first hours of Al exposure. The MeJA application decreased Al uptake and stimulated antioxidant pathways, which may counteract the toxic Al effects, protecting the photosynthetic apparatus in both cultivars, being more evident in the Al-sensitive cultivar.

Manganese (Mn) is an essential micronutrient for plants, and is necessary for biochemical and physiological processes. The objective of this research was to determine the early responses to Mn excess and its relation to antioxidant performance mechanisms and organic acid exudation in commercial barley cultivars. We determined early responses to Mn excess in four barley cultivars (Barke, Tatoo, Scarlett, Sebastian), which were subjected to increasing Mn concentrations (2.4-150-350-750-1500 µM Mn), pH 4.8, under nutrient solution during seven days. Results showed that plant growth parameters: biomass, length and relative growth rate (RGR) were negatively altered with the higher Mn treatments. Antioxidant performance such as antioxidant activity (AA) and antioxidant enzymes such as superoxidase dismutase (SOD) were activated in presence of excess Mn. Oxalate was the major organic acid roots exudate, and the cultivar Sebastian had the highest oxalate exudation. In conclusion, Tatoo and Sebastian are proposed as the most Mn tolerant cultivars given that the biomass parameters were not affected by increasing Mn doses, showing major oxalate exudation. It is suggested that the mechanisms associated to Mn alleviation could be attributed to SOD, AA and organic acid production, mainly oxalate, in tolerant cultivars (Sebastian, Tatoo) together to significant decrease of total phenols (TP) in shoot of sensitive cultivars (Barke and Scarlett). Non-enzymatic barriers were not related to early responses, and an enzymatic barrier and oxalate exudation were considered as early indicators of Mn stress, projecting that the tolerance of Mn-tolerant cultivars could increase under field conditions.

Highbush blueberry fruits are very perishable, decreasing quality and antioxidant potential during postharvest storage. Several preservation technologies to improve blueberries shelf life have been proposed. We evaluated the impact of fruit cold-storage and UV-C irradiation postharvest treatments on quality and antioxidant properties of berries from different blueberry cultivars grown in southern Chile. Berries of Legacy, Brigitta, and Bluegold cultivars were subjected to cold-storage (4°C, for 28 days) or UV-C irradiation (2.3 or 4.6 kJ m −2) before cold-storage (4°C) during 5 or 10 days. Then, fresh weight (FW), total soluble solids (TSS), titratable acidity (TiA), radical scavenging activity (RSA), total phenol content (TPC), and total anthocyanin content (TAC) were analyzed in whole fruits. During cold-storage, fruit FW was reduced (~20%) from day 7 onward, without variations among storage times. The irradiation of fruits with UV-C light also tends to reduce berry FW (~20%), but only in cultivar Legacy and in response to the highest UV-C doses. No significant differences were found in TSS or TiA of fruits by the effect of any treatments. Interestingly, UV-C irradiation induced greater antioxidant properties of blueberries. Bluegold and Brigitta fruits revealed increased RSA under 4.6 kJ m −2 doses. Also, Bluegold showed the highest levels of TPC at doses of 4.6 kJ m −2 of UV-C. Moreover, fruits of all cultivars exhibited increased TCA in response to the higher doses of UV-C. UV-C irradiation could be an interesting tool to improve antioxidant potential in highbush blueberries, which can negatively affect fruit quality for fresh consumption.

No abstract

No abstract