Non-destructive methods for fruit quality evaluation

Abstract

This work studies the evolution in time of several varieties of apples with application in quality storage maintenance. Two different methods were used to evaluate long-stored apples for better sorting and degradation assessment. The first method was laser photoacoustic spectroscopy for the detection of ethylene and ethanol compounds from the internal atmosphere of apples. The second method was multispectral imaging that measures the image and the spectrum combined and also can be used to address features such as ripening and external defects. The experiments showed that, the ethylene value decreases and the value of ethanol increases, which sometimes we may associate with a drift of the images toward darker tones, because the apple is slowly degrading. Non-invasive, real-time inspection can reveal when the degradation process begins, improving the capability of sorting, maintaining their quality and storability.

Ammonia measurement in human breath of subjects with Helicobacter pylori using photoacoustic spectroscopy

“…To collect clean breath air samples, we utilized aluminized multipatient collection bags kits, each containing 750 mL aluminium‐coated bags. These kits are specifically designed to collect multiple samples from patients and can hold a sample for a maximum of 6 h. Detailed descriptions of these kits can be found in the articles [10–15]. After the subject exhales through the mouth and the sample is collected, the gas from the sample is transferred into the detection cell and can be analyzed immediately or at a later time.…”

“…So, the study evaluates the ammonia gases founded in the human respiration (ABT) with or without H. pylori using the CO 2 laser photoacoustic spectroscopy method with regard to the CO 2 laser frequencies [10–14] (see Figure 2).…”

“…In contrast with other spectral systems, photoacoustic spectroscopy trace gas sensing technology is not to directly evaluate the change of light intensity and represent an indirect quantification process in the absence of background signal interference. For the reason that of these advantages, laser photoacoustic spectroscopy trace gas sensing is extensively solicitated in medical, industrial, environmental, monitoring, and other areas [9–14].…”

Analytical methods for the analysis of volatile natural products

“…In a similar study, several new methods based on PAS were developed to detect ethylene and ethanol compounds from the internal atmosphere of apples. 149 The non-invasive, real-time inspection methods can reveal when the degradation process begins, and can be used to improve the quality and storability of fruits.…”

Advance in application of rapid non-destructive testing technology in the detection of apple mold heart disease

“…With the development of science and technology, computer technology and spectral technology have been rapidly improved. Spectral technology has been widely used, with advantages such as low cost, non-destructive detection and fast analysis speed [12][13], and has been widely welcomed by many researchers in detecting the internal quality of apple [14][15] . To establish a relationship between the spectral reflectance or absorption rate of specific wavelength peaks of apples in a certain part or several parts according to the characteristic peak of apples and apple deterioration index, so as to distinguish the quality of apples [9] .…”