Gloss Evaluation of Curved-surface Fruits and Vegetables

Gloss measurements are used to evaluate the quality and appearance of a product, especially in cases where esthetic appearance is of importance. Most commercial glossmeters are designed for measuring products of flat surface and therefore are not suitable for food products because of their uneven, curved surface. A new generation of commercial glossmeters is recently available for confined areas, curved surfaces, and surfaces that are not uniform. This article provides a brief review of gloss measurement principles and methods for fresh fruits and vegetables. It reports on the gloss measurement of apples and other fresh products using a commercial glossmeter and a specially designed spectrometer-based gloss measurement prototype integrated with imaging and automatic sample positioning capabilities. Results showed that the prototype had a nonlinear relationship with standard gloss measurements. With the new setup, the gloss of apples was measured with the repeatability for 90% of the measurements being better than 16%, calculated as the ratio of the difference between maximum and minimum gloss values to the mean value in percent. Further research is needed to simplify the imaging/mechanical configuration and improve the coordinate calculation algorithm to achieve more accurate, repeatable gloss measurements.     

Spectroscopic Differentiation and Quantification of Microorganisms in Apple Juice

ABSTRACT: A fast and easy-to-operate Fourier Transform Infrared (FTIR) spectrometry-based approach was developed for microbial differentiation and quantification in apple juice. Eight different microorganisms were evaluated: Enterobacter cloacae, Salmonella typhimurium, Enterobacteraerogenes, Salmonella choleraesuis, Serratia marcescens, Pseudomonas vulgaris, Vibrio cholerae , and Hafnia alvei . FTIR spectroscopy combined with chemometrics could differentiate the microorganisms studied at low concentration level of 10³ colony-forming units (CFU) /mL in apple juice. The chemometric models developed to count microorganisms in apple juice were validated by an independent test set consisting of 18 samples and correlated against plate counts satisfactorily up to a detection limit of 10³ CFU/mL.     

Quality fruit

Non-destructive methods for determining quality are crucial to the agricultural industries. The authors describe a non-destructive ultrasonic measurement system that was developed to test the maturity, firmness and other quality-related properties of avocado and mango fruits