In-Situ Measurement of Fresh Produce Respiration Using a Modular Sensor-Based System

Abstract

In situ, continuous and real-time monitoring of respiration (R) and respiratory quotient (RQ) are crucial for identifying the optimal conditions for the long-term storage of fresh produce. This study reports the application of a gas sensor (RMS88) and a modular respirometer for in situ real-time monitoring of gas concentrations and respiration rates of strawberries during storage in a lab-scale controlled atmosphere chamber (190 L) and of Pinova apples in a commercial storage facility (170 t). The RMS88 consisted of wireless O2 (0% to 25%) and CO2 sensors (0% to 0.5% and 0% to 5%). The modular respirometer (3.3 L for strawberries and 7.4 L for apples) consisted of a leak-proof arrangement with a water-containing base plate and a glass jar on top. Gas concentrations were continuously recorded by the RMS88 at regular intervals of 1 min for strawberries and 5 min for apples and, in real-time, transferred to a terminal program to calculate respiration rates ( R O 2 and R CO 2 ) and RQ. Respiration measurement was done in cycles of flushing and measurement period. A respiration measurement cycle with a measurement period of 2 h up to 3 h was shown to be useful for strawberries under air at 10 °C. The start of anaerobic respiration of strawberries due to low O2 concentration (1%) could be recorded in real-time. R O 2 and R CO 2 of Pinova apples were recorded every 5 min during storage and mean values of 1.6 and 2.7 mL kg−1 h−1, respectively, were obtained when controlled atmosphere (CA) conditions (2% O2, 1.3% CO2 and 2 °C) were established. The modular respirometer was found to be useful for in situ real-time monitoring of respiration rate during storage of fresh produce and offers great potential to be incorporated into RQ-based dynamic CA storage system.

Developing of biophysical food for monitoring postharvest supply chains for avocado and potato and deploying of biophysical apple

“…The option for real-time monitoring would benefit, as stakeholders could directly see what is happening in the cold chains to take the proper actions. In the ideal case, the logger device could also include other relevant sensors (e.g., respiratory gases or air speed) (Geyer et al, 2018;Keshri et al, 2020). Note that in the current version, additionally to temperature, humidity can be measured by using a Hygrochron (DS1923) instead of a Thermochron (DS1921G and DS1922L) iButton at the surface.…”

“…Few studies have been conducted about novel fresh produce simulators monitoring temperature, humidity, or respiration (de Mello Vasconcelos et al, 2019;Geyer et al, 2018;Hübert and Lang, 2012;Keshri et al, 2020). A fruit simulator sensor device recently described by (Defraeye et al, 2017) was developed to monitor and analyze product temperature more realistically in order to improve storage and transport conditions in the cold chain.…”

A comprehensive review of intelligent packaging for fruits and vegetables: Target responders, classification, applications, and future challenges

“…Subsequently, the device was put to the test sequentially using strawberries under modified atmospheric and storage conditions in the absence of ambient air and with O 2 volume fractions gradually reduced from 21% to 16%, 8%, 4%, 2%, and 1% (balanced by N 2 ). The findings revealed that the proposed device can rapidly and accurately determine the respiration rate of fresh produce such as strawberries in real time, facilitating the regulation of the storage gas atmosphere of F&V. The team later reported continued monitoring of apple gas concentrations and respiration rates under varied storage conditions and throughout the storage period with gas sensors and modular respirometers (Keshri et al., 2020).…”

“…The environment to which the F&V are exposed is of critical significance for the quality of them, comprising an atmosphere with gas concentrations of ethylene, O 2 , and CO 2 , as well as temperature and humidity conditions. Respiration rates and their variation, commonly measured by analyzing O 2 consumption or CO 2 production per unit of time, contribute dramatically to post-harvest quality maintenance so they are a crucial parameter to control for extending the shelf life of F&V (Keshri et al, 2019(Keshri et al, , 2020. Therefore, assessing respiration rates is an indispensable tool for optimizing the design of packaging systems and maintaining optimal conditions within the storage system.…”

Development of a Controlled-Ventilation Box for Modified-Atmosphere Storage of Fresh Produce

“…These data transferred every minute to a PC by RMS88 aided in real-time decision-making in terms of changing the blower ON frequency. Use of such a compact and modular system for automatic data collection and wireless transmission for real-time monitoring was useful in determining the stored fresh produce behavior, especially without missing any data due to delays with the possibility of automation [23]. Further, the authors recommend a blower ON frequency of 6 min h −1 and 8 min h −1 suitable for sweet cherries stored at 10 • C. At a higher temperature though, the gas concentration did not deviate too much from the recommended limit; however, a further study is recommended to investigate a more suitable blower ON frequency for sweet cherries.…”