TY - JOUR A1 - Hübert, Thomas A1 - Lang, Cindy T1 - Artificial fruit: postharvest online monitoring of agricultural food by measuring humidity and temperature JF - International Journal of Thermophysics N2 - An online monitoring of environmental and inherent product parameters is required during transportation and storage of fruit and vegetables to avoid quality degradation and spoilage. The control of transpiration losses is suggested as an indicator for fruit freshness by humidity measurements. For that purpose, an electronic sensor is surrounded by a wet porous fiber material which is in contact with the outer atmosphere. Transpiration reduces the water content of the porous material and thus also the internal water activity. The sensor system, known as 'artificial fruit,' measures the relative humidity and temperature inside the wet material. Humidity and temperature data are collected and transmitted on demand by a miniaturized radio communication unit. The decrease in the measured relative humidity has been calibrated against the mass loss of tomatoes under different external influencing parameters such as temperature, humidity, and air flow. Current battery life allows the sensor system, embedded in a fruit crate, to transmit data on transpiration losses via radio transmission for up to two weeks. KW - Agricultural food KW - Relative humidity KW - Transpiration losses KW - Water activity PY - 2012 DO - https://doi.org/10.1007/s10765-011-1101-0 SN - 0195-928X SN - 1572-9567 VL - 33 IS - 8-9 SP - 1606 EP - 1615 PB - Springer CY - Dordrecht AN - OPUS4-27343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -