Gloss of fruits and vegetables

Abstract

A glossmeter, suitable for measuring the gloss on curved surfaces has been constructed. The gloss of ripe banana, green bell pepper, orange, tomato, eggplant and onion were checked with an incident laser light at 45° and 60°. Reflected light was collected by photosensors and the image was analysed using appropriate software. L, a, b, °Bx, pH and gloss of fruits and vegetables were checked once they reached the stage of ready to eat. Eggplant and green bell pepper presented the highest gloss properties under investigating conditions, while banana and unwaxed orange exhibited the lowest sheen. Results from our glossmeter were compared with a commercial glossmeter, designed to check gloss of flat surfaces. In such operations it was necessary to peel and flatten the skin. Gloss of the fruits and vegetables were ranked in a similar way by both apparatus. Linear correlation was found between results of gloss measured at 60° by both apparatuses. It must be emphasized that intact fruits cannot be checked by the commercial glossmeter because of their curved surfaces. © 1996 Academic Press Limited.