Abstract The present study assessed the physical, chemical, functional, and microbiological properties of cocoyam (Xanthosoma spp.) corm flour made from the Nazareno cultivar. The flour was initially submitted to a water-soaking process in order to reduce its high oxalate content. The soaked flour showed a high dietary fiber content (15.4% insoluble and 2.8% soluble fiber), and can be considered essentially an energy-rich food given its high starch content (60.5%), of which 85.04% was analyzed as amylopectin; it also showed a high potassium content (19.09 mg/g). The anti-nutritional component analysis showed low levels of oxalate (5.55 mg/g), saponins (0.10%) and tannins (0.07%), while phytates were not detected. The flour had a high water and oil absorption capacity (9 - 11 g/g at 90 and 100 °C; 1.2 g/g) and it gelatinized at between 81.81 - 89.58 °C. It was also microbiologically stable after storage for 9 months at room temperature. Development of a multipurpose flour from cocoyam corm could provide a value-added option for the local food industry.

AbstractThermal processing and production practices used in vegetables can cause changes in their phytochemical contents. Eggplant is characterized by its high antioxidant content. The objective of this work was to determine levels of anthocyanins, polyphenols, and flavonoids and antioxidant capacity in organically and conventionally grown eggplant prepared fresh or subjected to one of three thermal preparation methods: boiling, baking or steaming. The soluble and hydrolyzable polyphenols and flavonoids content were quantified by Folin-Ciocalteu and Aluminum chloride methods, respectively. Anthocyanins were quantified according to the pH differential method. Antioxidant capacity was determined by DPPH and ORAC methods. The results showed differences between organic and conventional eggplant for some variables although cultivation method did not have a consistent effect. Hydrolysable polyphenol content was greater, and soluble and hydrolysable antioxidant capacities were higher in organically grown eggplant, while anthocyanin content was greater in conventionally grown eggplant. Fresh eggplant produced under conventional cultivation had a much greater content of anthocyanins compared to that of other cultivation method-thermal treatment combination. In general, steamed eggplant contained higher total polyphenol and flavonoid levels as well as greater antioxidant capacity. Steamed eggplant from both conventional and organic systems also had high amounts of anthocyanins compared to other thermal treatments.

Avaliamos os efeitos de snacks feitos com amaranto desengordurado (Amaranthus caudatus L.) no metabolismo lipídico de pacientes com hipercolesterolemia moderada. O ensaio clínico contou com vinte e dois voluntários [30-65 anos, 11 homens, com colesterol total > 240 mg.dL-1, LDL-c 160-190 mg.mL-1, e triglicerídeos plasmáticos (TG) < 400 mg.mL-1] aleatoriamente distribuídos em dois grupos que receberam um snack de amaranto (50 g/dia) ou um placebo equivalente (snack de milho) por dois meses. Não houve diferenças significativas entre o amaranto e o placebo no colesterol total, LDL-c e TG, cujos valores foram, respectivamente, -8,4 e -5,7% (p = 0,17); -12,3 e -9,7% (p = 0,41) e -0,6 e -7,3% (p = 0,47). Entretanto, o consumo de snacks de amaranto reduziu significativamente o HDL-c: -15,2 vs. -4% (p = 0,03). Concluímos que o consumo de 50 g de amaranto extrusado por 60 dias não foi suficiente para reduzir significativamente LDL-c em pacientes com hipercolesterolemia moderada; além disso, observou-se significativa redução de HDL-c. Estudos com maior número de participantes e maior quantidade de amaranto são necessários para se testarem os seus efeitos no metabolismo humano.

We evaluated the effects of defatted amaranth (Amaranthus caudatus L.) snacks on plasma lipids in moderate hypercholesterolemic patients. Twenty-two subjects [30-65 years old), 11 males, with total cholesterol (TC) > 240 mg.dL-1, low-density cholesterol (LDL-c) 160-190 mg.dL-1 and plasma triglycerides (TG) < 400 mg.dL-1] were randomized in a double blind clinical trial to receive an amaranth snack (50 g/day) or equivalent corn snack (placebo) for 2 months. There were no differences between amaranth and placebo on TC and LDL-c, and TG respectively: -8.4 and -5.7% (p = 0.17); -12.3 and -9.7% (p = 0.41) and -0.6 and -7.3% (p = 0.47). However, amaranth snacks significantly reduced high-density cholesterol (HDL-c): -15.2 vs. -4% (p = 0.03). In conclusion, the intake of 50 g of extruded amaranth daily during 60 days did not significantly reduce LDL-c in moderate hypercholesterolemic subjects; furthermore there was a significant reduction in HDL-c. Studies with greater number of subjects and greater quantity of this food are necessary to test the effects of amaranth on lipid metabolism in humans.