Bioactive compounds and antioxidant activity in garambullo fruit (Myrtillocactus geometrizans) at different ripening stages.

Garambullo (Myrtillocactus geometrizans) is endemic in México, and although popularly consumed locally, its nutritional characteristics and value have not been studied in details. The objective of this work was to investigate the bioactive compounds and antioxidant activity in garambullo fruit from different sites at three ripening stages. Fruit from the three ripening stages (red, purple, and dark purple) were investigated for their physicochemical characteristics, hydrophilic (phenolic compounds, betalains, and ascorbic acid), and lipophilic (carotenoids, tocopherols, and fatty acids) bioactive compounds, using spectrophotometry, gas chromatography (GC-FID), and high-pressure liquid chromatography coupled to mass spectrometry (HPLC/DAD-ESI-MS). The antioxidant capacity was measured with the 2,2'-diphenyl-1-picrylhydrazyl and the ferric-ion-reducing antioxidant power assays. The color components of the fruit, chroma and a* values increased, whereas lightness (L*) and b* significantly decreased during ripening. Five betacyanins and four betaxanthins were tentatively identified with HPLC/DAD-ESI-MS, and betacyanins were more abundant than betaxanthins. Betalains content and antioxidant capacity of hydrophilic extracts significantly increased during ripening. Ten phenolic compounds were identified, with ferulic acid being the most abundant. Tocopherols were low (0.023-0.033 mg/100 g fw). Five fatty acids were abundant, and linoleic acid was the most important. Phenolic compounds, ascorbic acid, total carotenoids, and fatty acids decreased during fruit ripening. Garambullo fruit is rich in phytochemical compounds of importance for human nutrition and health. PRACTICAL APPLICATION: The physicochemical and bioactive compounds characterization in garambullo fruit is important to establish maturation and harvesting indices, postharvest strategies to preserve fruit quality and prolong postharvest life, promote the consumption and utilization of the fruit, and the designing of proper functional foods. In addition, the knowledge on the bioactive components might be useful to include this fruit in personalized nutritional approaches for patients with risks of certain chronic diseases. The methodology used in this study could be useful for the study of other fruits, especially those from the Cactaceae family.

Overweight and Obesity Are Positively Associated with Serum Copper Levels in Mexican Schoolchildren.

Due to its relationship with oxidative stress and inflammation responses, obesity and its cardiometabolic implications have been related with serum copper (Cu). Hence, we analyzed the association of overweight (OW) and obesity (OB) status and cardiometabolic traits with serum Cu level in Mexican schoolchildren. Anthropometrical data and cardiometabolic traits were analyzed in this cross-sectional study. Serum Cu level was measured by inductively coupled plasma mass spectrometry. The study involved 191 schoolchildren (93 girls and 98 boys) with a mean age of 8.054 ± 1.170 years. Children with OW and OB had higher serum Cu levels than children with normal weight (NW) (mean difference: OW vs NW = 51.85 µg dL-1, OB vs NW = 47.22 µg dL-1, p < 0.001). In a multiple linear regression model, OW and OB status were positively associated with serum Cu levels (ßOW = 49.85, 95% confidence interval (95% CI) 35.84-63.87, p < 0.001; ßOB = 44.38, 95% CI 27.70-61.05, p < 0.001). We did not identify any significant association between cardiometabolic traits and serum Cu level. In conclusion, our results show an association of the presence of OW and OB with higher serum Cu levels, for the first time in Mexican schoolchildren. However, further functional studies are needed to better understand the role of Cu in the pathophysiology of obesity.

Gastrointestinal metabolism and bioaccessibility of selected anthocyanins isolated from commonly consumed fruits.

There is uncertainty about the identity of digestive metabolites of anthocyanins because many are naturally present in foods and/or are formed from other phenolic compounds during the digestive process. Studies using pure anthocyanins are needed to clarify this uncertainty. In this study, selected anthocyanins were purified from common fruits and individually subjected to gastric and small intestinal digestion in vitro to determine their stability, metabolites generated and bioaccessibility. Anthocyanins were highly stable during the gastric phase of simulated digestion (p > 0.05). The recovery of anthocyanins decreased during the small intestinal phase of digestion (p < 0.05). Stability was dependent on anthocyanidin structure and type of glycation (p < 0.05). Gastric and gastrointestinal phases mainly contained anthocyanins as bioaccessible flavylium cations and chalcones. Expected anthocyanin metabolites (i.e., phenolic acids and phoroglucinaldehyde) were not detected in chyme. Deglycation of anthocyanins during simulated digestion was quite limited and the bioaccessibility of intact anthocyanins was very low (0.07-2.21%).

Sex-Specific Association between Fasting Plasma Glucose and Serum Selenium Levels in Adults from Southern Mexico.

Selenium (Se) is an essential trace element that by its antioxidant properties has been studied to elucidate its participation in the development of obesity and type 2 diabetes. We evaluated the association between cardiometabolic traits and serum Se levels in a sample of adults from southern Mexico. In 96 nondiabetic individuals, anthropometric data and clinical biochemistry measurements were analyzed. Serum total Se levels were measured with inductively coupled plasma mass spectrometry (ICP-MS). Serum Se level in the whole sample was 10.309 ± 3.031 µg mL-1 and no difference between the women and men was observed (p = 0.09). Additionally, fasting plasma glucose (FPG) was significantly associated with serum Se level (ß = -0.07 ± 0.03, p = 0.02, analysis adjusted for age, sex and BMI). Furthermore, sex shows significant interaction with FPG on the serum Se levels (p = 0.01). A follow-up analysis revealed the particular association between FPG and Se levels in women (ß = -0.10 ± 0.04, p = 0.01). In conclusion, our data evidenced a women-specific association between FPG and serum Se levels in a sample of adults from southern Mexico.

Bioaccessibility of fat-soluble bioactive compounds (FSBC) from avocado fruit as affected by ripening and FSBC composition in the food matrix.

Dried fruit pulp and oil from avocado fruit (Persea americana, Cv Hass) at five different ripening stages were digested in vitro to determine the bioaccessibility of several fat-soluble bioactive compounds (FSBC). Viscosity, particle size, ζ-potential and lipolysis were evaluated and related to the bioaccessibility of the tested compounds. Fatty acids were more bioaccessible than carotenoids and tocopherols. The viscosity of gastrointestinal medium was related to the initial fruit firmness and modulated the bioaccessibility of neoxanthin, violaxanthin, lutein and luteoxanthin, while particle size and ζ-potential influenced the bioaccessibility of fatty acids. Lipolysis degree highly altered the bioaccessibility of luteoxanthin, pheophytin b, and α-tocopherol indicating that these digestive events are highly involved in the bioaccessibility of FSBC. In summary, FSBC from avocado fruit are highly bioaccessible, but their bioaccessibility depends on fruit ripening stage and FSBC type and concentration.