Effect of Thermal Treatment on Physicochemical Stability and Antioxidant Properties of Locally Available Underutilized Star Fruit Juice

Abstract

Industrial processing of the fruit juice is responsible for the changes in some quality attributes. Thermal treatment is a most applicable operation for any processing and it affects the physicochemical and antioxidant properties of the juice. This study was conducted to observe the changes in some physical properties and the bioactive compounds of star fruit (Averrhoa carambola L.) juice during thermal treatment at 70°C, 80°C and 90°C for 10, 20, 30 and 40 min by a temperature-controlled water bath. During thermal treatment of the juice pH and browning index increased significantly (P≤ 0.05) with time and increasing temperature whereas the Cloud index of the juice decreased. No significant variation (P≥ 0.05) noticed in the case of total soluble solids. Color differences gradually increased in case of color parameter (0 to 7.83 ± 0.20) and negatively increased in case of (0 to -7.33± 1.00). Irregular results observed for and maximum difference (3.01±0.08) noticed at 90°C for 40 min. The highest overall color change (∆E= 11.04±0.76) observed when the juice treated at 90°C for 40 min. In consideration of the bioactive compounds, maximum ascorbic acid estimated (24.17±0.70mg/100ml) in fresh juice and with rising temperature and time it decreased. β-carotene also decreased significantly during heat treatment. The Total Polyphenol Content (TPC) found in fresh juice as (540.08±16.64 mg GAE/100 ml) and it was not changed in a regular manner with temperature change. Flavonoid content increased significantly (P≤0.05) when the juice was heat-treated at 70°C and 80°C while no significant change observed at 90°C. Maximum DPPH scavenging activity found in fresh juice (60.19±1.39%) and decreased to (53.83±1.43%) when 90°C temperature was applied for 40 min. This study may help to find out the nutritional value of locally available star fruit and physicochemical changes of this fruit juice during thermal processing.

Physicochemical, antioxidant and microbiological behavior of soursop purees during thermal treatment

“…However, the vision of all samples is quite similar, its color was white. This result agreed with Shourove et al (2020) and Chutintrasri and Noomhorm (2007), those authors found the ∆E value of pineapple puree and star fruit juice, respectively, increased with time and treatment temperature. The value has different letters superscript show statistically significant differences at the α = 0,05 confidence level.…”

Determination of Antioxidant Activity and Total Tannin from Drumstick (Moringa oleifera Lam.) Leaves Using Different Solvent Extraction Methods

“…A previous study reported that the increasing temperature at a certain level accelerates the extraction, but after that level, it decreased because of the reduced stability of phenolic compounds (Dorta et al, 2012). The lower TPC value was also observed at the hightemperature treatment of star fruit juice due to the destabilization of the phenolic structure (Shourove et al, 2020). The present study revealed, Moringa leaves as a potential source of polyphenol, which Moringa leaves had contained much higher total polyphenol (mg GAE/ 100g) than some Indian fruits and vegetables such as pomegranate (671.1 ± 18.5), mango (440.6 ± 16.6), kinnow (354.9 ± 12.5), banana (362.4 ± 17.2), beetroot (909.5 ± 37.4), bringal (292.3 ± 12.7), bitter gourd (226.5 ± 10.5), black carrot (1028.6 ± 23.4), spinach (233.5 ± 20.2) (Singh et al, 2016).…”

“…Again, the antioxidant value was found to decrease with the increasing temperature and the extraction time, which maybe because of the destruction of the chemical composition of the polyphenolic compounds, ascorbic acid and chlorophyll content of the Moringa leaf (Sreelatha and Padma, 2009;Nobossé et al, 2018). Those study revealed Moringa leaves as a potential source of antioxidant compounds, which showed higher antioxidant activity than some typical fruit juice such as: lemon (63%), orange (61%), star fruit (60.19%), mandarin (52%), grapefruits (58%) (Shourove et al, 2020).…”

Antioxidant and Antibacterial Activities of Four Underutilized Fruits of Bangladesh

“…2 showed that total flavonoid contents of the Taikor had a significantly (p ≤ 0.05) higher amount of flavonoid (148.18 ± 0.40 mg QE/100 ml) than the Roselle (118.87 ± 1.09 mg QE/100 ml), Olive (92.30 ± 0.80 mg QE/100 ml), and Jujube (90.19 ± 0.30 mg QE/100 ml). All the fruits were found to contain higher amounts of flavonoids than another underutilized fruit Carambola (2.56 ± 0.40 mg QE/100 ml) as reported by Shourove et al (2020). Mudoi et al (2012) also reported that the methanolic extract of G. pedenculata had contained 71.4 ± 0.84 mg QE/100 g on dry weight basis.…”