Biochemical and nutritional characterization of dragon fruit (Hylocereus species).

Nutritional and biochemical composition of dragon fruit (Hylocereus) species H. undatus (fruits with white pulp and pink skin), and H. polyrhizus (fruits with red pulp and pink skin) were investigated to develop the nutritional composition data for dragon fruit and compare the difference between H. undatus and H. polyrhizus. The pH, TSS, total sugar, moisture, ash, protein, and dietary fibre content varied between 4.8 and 5.4, 8-12%, 5.13-7.06%, 82-85%, 0.7-0.85%, 0.90-1.1% and 0.8-1.0%, respectively. Total phenolics and flavonoids content varied between 25 and 55 mg GAE and 15-35 mg CE per 100 g, respectively. H. polyrhizus have a significantly high quantum of phenolics and antioxidant potential than H. undatus. 100 g fruit contained about 120-200 mg K, 30-45 mg Mg, 20-45 mg Ca, 20-35 mg P, 0.70-1.5 mg Fe, and 0.20-0.40 mg Zn. Vitamin C was found maximum (6 mg/100 g), followed by vitamin E (150 µg), pantothenic acid (50 µg), and vitamin K1 (25 µg). It is an ideal fruit for maintaining good health as it has low calories.

Juá fruit (Ziziphus joazeiro) from Caatinga: A source of dietary fiber and bioaccessible flavanols.

Fruits from Ziziphus joazeiro from Mata Paraibana (MP), Borborema (BB), Agreste (AG) and Sertão Paraibano (SP) were assessed to determine their morphological characteristics, nutritional composition, content and bioaccessibility of phenolic compounds and antioxidant activity. In general, juá fruits presented ovoid shape, high moisture (65.33-72.53%), low acidity, with succinic acid being the predominant organic acid, and high dietary fiber content (8.98-10.81%), mostly insoluble fibers (5.72-8.02%). Fruits from MP presented the highest amounts of free phenolic compounds (24.27 mg/100 g) and the highest antioxidant activity in the DPPH, FRAP and ORAC assays. In MP fruits, epigallocatechin gallate (12.04 mg/100 g) was the major compound, while in fruits from other states, phenolic compounds were the major compounds. The bioaccessibility of catechin, epicatechin, epicatechin gallate, epigallocatechin gallate, procyanidin and syringic acid varied among fruits from different regions. Fruits from SP presented the highest phenolic content in the bioaccessible fraction and highest antioxidant activity in all assays. The findings of this study indicate that juá is a non-acidic fruit with highest moisture, source of fiber, majority insoluble fibers and bioaccessible flavanols.

Effect of ultrasound treatment on visual color, vitamin C, total phenols, and carotenoids content in Cape gooseberry juice.

Strong interest of consumers in acquiring minimally processed foods that conserve the different micronutrients has raised the need to study the effect of food processing methods on quality attributes. The aim of the study was to determine the effect ultrasound treatment on color, and the bioactive compounds (ascorbic acid, total phenols, carotenoids, and provitamin A) of Cape gooseberry juice. Color values, ascorbic acid, total phenols, carotenoids, and Retinol Activity Equivalent (RAE) were measured. The results indicate significant reductions (p<0.001) in the chromaticity, yellowing index (IY), and acid ascorbic content was observed in all the juice samples sonicated. But there were significant increases (p<0.001) in hue, the total color differences (TCD), total phenols, carotenoids, and RAE value as compared to control. The results demonstrated that ultrasound processing increase the availability of carotenoids, total phenols and RAE in Cape gooseberry juice.