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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #338954
Research Project: Defining, Measuring, and Mitigating Attributes that Adversely Impact the Quality and Marketability of Foods

Location: Healthy Processed Foods Research

Title: Nondestructive determination of dry matter and soluble solids content in dehydrator onions and garlics using a handheld visible and near infrared instrument

Author
item CHAIYA, JANTRA - Kasetsart University
item SLAUGHTER, DVID - University Of California
item Liang, Peishih
item SIWALAK, PATHAVEERAT - Kasetsart University

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/10/2017
Publication Date: 7/31/2017
Citation: Chaiya, J., Slaughter, D., Liang, P., Siwalak, P. 2017. Nondestructive determination of dry matter and soluble solids content in dehydrator onions and garlics using a handheld visible and near infrared instrument. Postharvest Biology and Technology. 133:98-103. doi: 10.1016/j.postharvbio.2017.07.007.

Interpretive Summary: The research used a handheld visible/near-infrared spectrophotometer to non-destructively identify dry matter and soluble solids contents in whole, fresh onions and garlic in near real-time (less than 5 seconds) for the dehydration industry, which currently uses a slow drying process (hours to days) to determine both characteristics of produce to establish price. The statistical models built based on the spectral data showed outstanding results with onions and good results with garlic. The results suggested that the instrument has great potential to aid in dried onion and garlic production process as a rapid, non-destructive technique to identify dry matter and soluble solids contents in onions and garlic.

Technical Abstract: A non-destructive method based on visible and near-infrared spectroscopy was investigated for determining the dry matter and soluble solids contents of dehydrator onions at the base, equatorial, and shoulder locations and of garlic cloves at the equatorial location. The interactance spectrum (400-1000 nm) of each sample was measured within 5 s using a handheld spectrometer with an optical design of 0° angle between the incident illumination and the detection view. The spectral data were used to develop partial least square regression models to predict the dry matter and soluble solids contents. The results showed that the onion model predictive performance at the equator location was better than the performance at the shoulder and base locations. For the dry matter and soluble solids contents, the coefficient of determination (R2) values for the onion models were 0.96 and 0.97, respectively, and the R2 values for the garlic models were 0.87 and 0.71, respectively. The outstanding results suggested that the handheld instrument has great potential to aid in onion and garlic production processing as a rapid, non-destructive technique to identify the dry matter and soluble solids contents in the field or in an industrial setting.