Chemical Sensors for Farm-to-Table Monitoring of Fruit Quality

Abstract

Farm-to-table operations produce, transport, and deliver produce to consumers in very different ways than conventional, corporate-scale agriculture operations. As a result, the time it takes to get a freshly picked fruit to the consumer is relatively short and the expectations of the consumer for freshness and quality are high. Since many of these operations involve small farms and small businesses, resources to deploy sensors and instruments for monitoring quality are scarce compared to larger operations. Within stringent power, cost, and size constraints, this article analyzes chemical sensor technologies suitable for monitoring fruit quality from the point of harvest to consumption in farm-to-table operations. Approaches to measuring sweetness (sugar content), acidity (pH), and ethylene gas are emphasized. Not surprisingly, many instruments developed for laboratory use or larger-scale operations are not suitable for farm-to-table operations. However, there are many opportunities still available to adapt pH, sugar, and ethylene sensing to the unique needs of localized farm-to-table operations that can help these operations survive and expand well into the future.

Ambient Parameter Monitoring in Fresh Fruit and Vegetable Supply Chains Using Internet of Things-Enabled Sensor and Communication Technology

“…The gaseous plant hormone ethylene enhances metabolic processes in many fruit and vegetables, but especially stimulates ripening in climacteric fruits [ 23 ]. Already extremely low concentrations can affect sensitive products [ 23 , 50 ]. Detrimental effects include accelerated senescence [ 23 ], loss of chlorophyll and yellowing in green-colored vegetables [ 16 , 22 , 23 ], accumulation of bitter compounds in carrots and parsnips [ 16 , 22 , 51 ] and excessive flesh softening, e.g., in kiwifruit and watermelons [ 51 , 52 ].…”

Sensors and Instruments for Brix Measurement: A Review

“…The different stages of harvest maturity are shown in Figure 1 . Sugar content is one of the measures used to judge the various stages of maturity [ 3 ]. Hence, it is the pivotal factor in agriculture, the food industry, winemaking and brewing.…”

Fruit ripeness sensors based on poly(lactic acid)/polyaniline solution blow‐spun fibrous membranes

“…12 Gas sensors have attracted a great deal of interest of researchers in the last years. 13,14 Adsorbed molecules on their surface may change the sensor physicochemical character in such a manner as to cause variations in optical properties, color, resistance, and conductive responses. The interaction may result from weak secondary bonding as van der Waals forces or through chemical reactions.…”

“…Together, they may convert a non‐electrical response, such as that resulting from the adsorption of gas onto the sensor surface, into an electrical signal prone to human handling and processing 12 . Gas sensors have attracted a great deal of interest of researchers in the last years 13,14 . Adsorbed molecules on their surface may change the sensor physicochemical character in such a manner as to cause variations in optical properties, color, resistance, and conductive responses.…”