Ultrasonic‐assisted extraction (UAE) and microwave‐assisted extraction (MAE) were used for the extraction of bioactive peptides from pineapple byproducts. Independent extraction parameters for UAE were ultrasonic amplitude (60–100%), extraction time (10–30 min), and solvent to material ratio (20–40 mL/g), whereas for MAE independent variables were microwave power (100–300 W), irradiation time (5–15 min), and feed to solvent ratio (1:8–1:12 g/mL). The optimized extraction conditions were 99.96%, 26.83 min, and 20.96 mL/g for UAE and 100 W, 8.99 min, and 1:8 g/mL for MAE. The optimized extraction resulted in total sugar, protein content, and proteolytic activity of 15.71 ± 0.03 mg/mL, 4.01 ± 0.04 mg/mL, and 196.46 ± 3.29 U/mL, respectively, whereas 33.87 ± 0.03 mg/mL, 2.50 ± 0.01 mg/mL, and 154.08 ± 1.49 U/mL for MAE, respectively. Scanning electron microscopy was used to observe the morphology of sample during extraction. Molecular weight determination showed that the major protein band in the extracts (UAE and MAE) was at ∼23 kDa which corresponded to bromelain. Furthermore, pineapple crown protein extract obtained by UAE showed high proteolytic activity (>80% relative). The present study indicated that bromelain and other bioactive peptides from pineapple byproducts have potential in food, feed, and pharmaceutical products development.Practical ApplicationsThe conventional extraction techniques for bioactive compounds are time‐consuming and less efficient. The use of advance extraction techniques like microwave‐ and ultrasonication‐assisted extraction techniques can increase the extraction yield with better recovery of bioactive compounds. Pineapple byproducts are rich source of bioactive compounds and bromelain. The effective utilization of pineapple byproducts for the extraction of bromelain and other bioactive peptides will offer an effective solution for minimizing the organic waste and provide an efficient source of bioactive peptides for application in various food products.

No abstract

Hybrid pectin and resistant starch–based hydrogel beads loaded with bromelain using the extrusion gelation method were prepared and evaluated to enhance the activity of bromelain during gastrointestinal passage and thermal processing. The solutions of pectin–resistant starch with bromelain were dropped into the gelation bath containing calcium chloride (0.2 M) solution to develop various types of hydrogel beads. The physicochemical characteristics of the synthesized hydrogel beads were evaluated. The ratio (4.5:1.5 w/w) of pectin and resistant starch concentration significantly (p < 0.05) enhanced the encapsulation efficiency (80.53%). The presence of resistant starch resulted in increased entrapment of bromelain, improved swelling properties with sustained release behavior, and improved gastric stability than pectin hydrogels alone. The swelling of hydrogel beads was higher at pH 7.4 than pH 1.2. Optimized batch of hybrid pectin/resistant starch exhibited a spherical shape. Optical and scanning electron microscopy showed a more packed and spherical shape from the pectin/resistant starch hydrogel bead network. Fourier transformation infrared spectroscopy was also used to confirm the presence of bromelain in the hydrogel beads. The encapsulated bromelain in the pectin/hi-maize starch beads produced at a pectin/hi-maize ratio of 4.5:1.5 (percent w/w; formulation P4) obtained the highest relative bromelain activity in all heat treatments including at 95°C, whereas the highest activity of free bromelain was found only at 30°C. Bromelain encapsulated in hydrogels released at a faster rate at simulated intestinal fluid (SIF, pH 7.4) than at simulated gastrointestinal fluid (SGF, pH 1.2).

No abstract