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Summary Grapefruit juice was investigated using pulsed electric fields (PEF) with (electric field strengths: 0, 5, 10, 15, 20 and 25 kV cm−1; flow rate: 80 mL min−1; pulse frequency: 1 kHz at 40 °C for 600 μs). Total phenolics, DPPH, total antioxidant capacity (TAC), total anthocyanins, total carotenoids, sugars and physicochemical properties of grapefruit juice were studied. In addition, the effect of PEF treatment on micro‐organisms was also observed. Results indicated that no significant change was observed in pH, Brix, titratable acidity, sugars, total anthocyanins and colour attributes with the increase in pulsed electric strength as compared to control treatment. However, significant decrease in nonenzymatic browning (NEB) and viscosity while an increase in cloud value, DPPH, TAC, total phenolics and total carotenoids, while reduction in the activity of micro‐organisms, was also observed with the increase in pulsed electric strength as compared to control treatment. This study suggested that PEF at 25 kV cm−1 could improve the quality of grapefruit juice.

Biodegradable films, with starch as a matrix, were developed and reinforced with wheat and corn hulls. The effect of the particle size of the filler on the microstructure and mechanical and barrier properties of starch‐based films was investigated. We observed that the addition of hulls enhanced the modulus, tensile strength, and impact strength of the starch matrix at the expense of its elongation. The water‐vapor transmission rate results show that corn starch was more efficient in reducing the water‐vapor permeability than wheat hulls. Scanning electron microscopy observations indicated that the compatibility of both fillers with the matrix was quite good; this was expected because all of the components used in this study were hydrophilic and exhibited polar behavior. Optical microscopy and X‐ray diffraction observations indicated that the processing conditions did not affect the crystalline and geometric structures of the hulls. Because all of the components used in this study were from food resources, the films could also be used for edible packaging. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45159.

Starches used to develop biodegradable composites belong to different botanical sources that exhibit different microstructures and morphologies. This results in confused relationship and no comparison of data for applications. In this work, the most popular ten different starches were used as model materials to investigate the relationship between starch microstructure and the performance of poly(lactic acid) (PLA)/starch composites. It was found that: (a) composites filled with either well‐sized (small‐sized and non‐agglomerated) starch granules or those containing high amylose content (G‐50 and G‐80) improves the reinforcing ability of PLA, with least reduction in deformation; (b) aggregation tendency of small‐sized starch granules can be controlled using surface modification approach that not only reduces the phase‐separation between starch and PLA but also improves the dispersion; and (c) no discernible relationship exists between the starches, from different botanical sources, and the thermal performance of PLA/starch composites. The results provide practical guidelines to develop starch‐based biodegradable composites for commercial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45504.