Optimization of Pectin Extraction from Peel of Dragon Fruit (Hylocereus polyrhizus)

As assessment of shelf life increasing competence of pectin (Zucchini) based edible coating on tomatoes

The most recent advancement in food packaging research involves improving the shelf life of perishable foods by utilising bio-based resources that are edible, eco-friendly, and biodegradable. The current study investigated the effect of edible pectin coating on mature green tomatoes to improve shelf life and storage properties. Zucchini pectin was used to make edible coating. The antimicrobial and antioxidant properties of extracted pectin were investigated. The findings indicated that the extracted pectin had antimicrobial (Staphylococcus aureus, Escherichia coli, and Aspergillus niger) and antioxidant (34.32% at 1 mg/mL) properties.Tomatoes were immersed in pectin solutions of varying concentrations, 1, 3, and 5% (w/v). Physiological evaluations of weight loss, total sugar content, titratable acidity pH, and ascorbic acid were performed on tomatoes during their maturing stages of mature green, light red, pure red, and breaking. Coating the tomatoes with pectin (5%) resulted in minimal weight loss while increasing the retention of total sugar, ascorbic acid, and titratable acidity. The shelf life of the pectin-coated tomatoes was extended to 11 days, while the uncoated control tomatoes lasted 9 days. Thus, a 5% edible pectin solution was found to be effective in coating tomatoes. The current study suggests that using 5% pectin as an edible coating on tomatoes can delay/slow the ripening/maturing process while also extending the shelf-life of tomatoes without affecting their physiochemical properties, which is scalable on a large scale for commercial purposes.

Pectin extraction from citron peel: optimization by Box-Behnken response surface design

In this study, the effect of acidic extraction conditions (time of 30-90 min, temperature of 75-95 °C and pH of 1.5-3) on the yield and degree of esterification (DE) of citron peel pectin was investigated applying Box-Behnken design. The highest production yield of pectin (28.31 ± 0.11%) was achieved at extraction time of 90 min, temperature of 95 °C and pH of 1.5, as optimal extraction conditions, which was close to the predicted value (29.87%). Under optimum extraction conditions, the DE and the emulsifying activity were 51.33 and 46.2%, respectively. In addition, the emulsions were 93.9 and 93.5 stable at 4 °C, 93.7 and 93.1 at 23 °C after 1 and 30 days, respectively. The determination of flow behavior showed that the pectin solutions had a Newtonian behavior at low concentrations (< 1.0% w/v), while this behavior was changed to pseudoplastic with increasing concentration.

Optimization of aqueous pectin extraction from Citrus medica peel

In this study, the effect of aqueous extraction conditions (temperature of 70-90°C, time of 60-180min, and liquid/solid ratio (LSR) of 20-40v/w) on the yield and degree of esterification (DE) of Citrus medica peel pectin was studied using a Box-Behnken design. The highest production yield of pectin (21.85±0.35%) was obtained at temperature of 90°C, extraction time of 180min and LSR of 40v/w as optimum extraction conditions which was close to the predicted value (24.13%). In these extraction conditions, the DE and the emulsifying activity were 77.2 and 46.5%, respectively. Also, the emulsions were 90.30 and 90% stable at 4°C, and 83.87 and 83.50% at 25°C after 1 and 30days, respectively. The determination of flow behavior showed that the pectin solutions had a Newtonian behavior at low concentrations (0.1, 0.5 and 1.0%w/v), while in higher concentration (2.0%w/v), the pseudoplastic flow behavior became dominant.

Effect of Drum Drying on Physico-chemical Characteristics of Dragon Fruit Peel (Hylocereus polyrhizus)

Dragon fruit (Hylocereus polyrhizus) peel is high in antioxidants and fiber; however, it is discarded during processing. In this study, changes in physico-chemical properties of dragon fruit peel after drum drying were determined. Ground dragon fruit peel was drum dried at 1 rpm with 2 bar steam pressure, then analyzed for physical, chemical and functional properties. The betacyanin content was twofold higher in drum-dried powder (41.55 mg/g dm) than in a fresh sample (80.21 mg/g dm), yet up to 98.62% of the total phenolic content was retained with a 3.328 mg trolox/g dm reduction in the radical scavenging activity. The density of the powder was 0.1315 g/mL with 51.44% soluble in water. The functional properties determined included water holding capacity (2.523 g water/g sample), oil holding capacity (3.565 g oil/g sample) and swelling capacity (6.233 mL/g). The results of this study indicate that drum-dried dragon fruit peel can be considered to contain potentially functional ingredients.

Antidiabetic and antihyperlipidemic effects of the stem of Musa sapientum Linn. in streptozotocin-induced diabetic rats

BACKGROUND

Musa sapientum Linn. is a herbaceous plant of the Musaceae family. It has been used in India for the treatment of gastric ulcer, hypertension, diarrhea, dysentery, and diabetes. The antidiabetic effect of the fruit, root, and flower has been demonstrated. The aim of the present study was to assess the antidiabetic and antihyperlipidemic effects of the stem of M. sapientum Linn.

METHODS

Diabetes was induced in rats by streptozotocin injection (45 mg/kg, i.p.). Diabetic rats were treated for 2 weeks with different doses of lyophilized stem juice of M. sapientum Linn. (25, 50, and 100 mg/kg) to select the most effective dose. The effects of 4 weeks treatment with this dose (50 mg/kg) on fasting and postprandial plasma glucose (FPG, PPG) levels, body weight, lipid profile, HbA1c, insulin, liver enzymes (i.e. glucokinase, glucose-6-phosphatase and 3-hydroxy-3-methylglutaryl coenzyme A [HMG-CoA] reductase) and muscle and liver glycogen were evaluated.

RESULTS

The most effective dose of lyophilized stem juice of M. sapientum Linn. was 50 mg/kg. Four weeks treatment with this dose resulted in significant decreases in FPG and PPG (P < 0.05). Serum insulin increased (P < 0.05) whereas HbA1c decreased (P < 0.05). Diabetes-induced changes to the lipid profile, muscle and liver glycogen, and enzyme activity (i.e. glucokinase, glucose-6-phosphatase, and HMG-CoA reductase) were restored near to normal levels (P < 0.05).

CONCLUSION

Diabetic rats responded favorably to treatment with lyophilized stem juice of M. sapientum Linn., which exhibits antidiabetic and antihyperlipidemic effects.

Application of ionic liquids in the microwave-assisted extraction of pectin from lemon peels

Microwave-assisted extraction of pectin from lemon peels by using ionic liquid as alternative solvent was investigated. The extracted pectin was detected by Fourier transform infrared spectra. The extraction conditions were optimized through the different experiments in conjunction with the response surface methodology. A pectin yield of 24.68 % was obtained under the optimal parameters: the extraction temperature of 88°C, the extraction time of 9.6 min, and a liquid-solid ratio of 22.7 ml · g(-1). The structure of the pretreated lemon peel samples and the samples after microwave-assisted extraction were characterized by a field emission scanning electron microscope.