Safety and quality issues in summer squashes using handheld portable NIRS sensors for real-time decision making and for on-vine monitoring

Abstract

BACKGROUND: Portable handheld near infrared spectroscopy (NIRS) instruments currently present enormous advantages in terms of size, weight and robustness. They also provide fast, precise information that can be obtained in situ, and represent a viable option for controlling vegetable safety and quality during the growth period. The aim of this research was to evaluate three handheld portable NIRS instruments for in situ and real time analysis of intact summer squashes. 221 summer squashes were analyzed by traditional methods and used to develop calibration models for morphological, safety and quality parameters. Additionally, the longitudinal distribution of nitrate content in summer squashes weighing over 400 g was also studied, and the evolution of this parameter during the harvest period was also tracked to determine which summer squashes and which zones (peduncle, equatorial or stylar) of the vegetable could be earmarked for baby food production.

RESULTS: The robustness of the calibration models obtained confirmed the expectations raised by NIRS technology for morphological, safety and quality control of individual summer squashes, and the models developed with the MicroNIR-1700 instrument were those which proved more accuracy and precision, being the peduncle zone the part that presents a higher content in nitrates.

CONCLUSIONS: It is in the peduncle zone, therefore, where measurements of this parameter must be carried out to decide on the destination of the harvested product. Additionally, summer squashes picked at the end of the harvest are those which must be used for baby food production.