A novel noninvasive and cost-effective handheld detector on soluble solids content of fruits. (September 2019)

• Record Type: Journal Article
• Authors: Guo, Wenchuan; Li, Weiqiang; Yang, Biao; Zhu, ZhuoZhuo; Liu, Dayang; Zhu, Xinhua
• Is Part Of: Journal of food engineering. Volume 257(2019)
• Page Start: 1
• Page End: 9
• Publication Date: 2019-09
• Subjects: Fruit -- Sweetness -- Detector -- Portable -- Non-destructive -- Visible/near-infrared spectrometer; Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Analyse -- Périodiques; Aliments -- Recherche -- Périodiques; 664.005
• DOI: 10.1016/j.jfoodeng.2019.03.022
• Languages: English
• ISSNs: 0260-8774

Abstract

Abstract: Soluble solids content (SSC) is an important parameter for determining sweetness, maturity, and price of fruits. A fast, noninvasive, and cost-effective portable SSC detector is appreciated by fruit planters, processers, sellers, and consumers. The study developed a handheld non-destructive SSC detector which mainly consisted of a visible/near-infrared (Vis/NIR) micro-spectrometer over the wavelength of 650–1100 nm, a Raspberry Pi board, a micro-halogen lamp, a self-made "Y" shape optical fiber probe (including an incident optical fiber and a reflection optical fiber), a lithium battery, and a display. The application software developed by python language was designed to collect diffuse reflection spectra, to preprocess spectra by using Savitzky–Golay smoothing method, and to calculate the SSC of fruits based on smoothed spectra and established partial least square regression models. Kiwifruits, nectarines, and apricots, collected from several orchards, were used as fruit samples to evaluate the detection performance of the developed SSC detector. The test showed that the root-mean-squares errors of the developed SSC detector operating in Vis/NIR range were 0.9%, 0.7%, and 0.8% for kiwifruits, nectarines, and apricots, respectively. The determined SSC value could be shown on the display in 2 s after triggering SSC measurement. Moreover, the detector was just about 550 g in weight. The developed novel handheld SSC detector is a convenient and fast tool for measuring SSC of fruits nondestructively. Highlights: A portable fruit sweetness detector operating in Vis/NIR range was developed. A "Y" shape optical fiber was developed to transmit and receive light. Raspberry Pi board was used as controller and the software was developed by Python. Soluble solids content could be given in 2 s after triggering measurement. The cost of the detector was low and its mass was about 550 g.