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BACKGROUND RESULTS CONCLUSION Identifying the best strawberries to produce colour stable nectars is a priority for the juice industry. Although riper strawberries produce nectars with better colour stability, variability between cultivars means that surface colour cannot be used as a single quality attribute to determine stability. Conductivity and bio‐impedance measurements can be used to differentiate ripeness of strawberries. The commercially available PEF Control System (ELEA) can measure cell disruption by measuring conductivity at different frequencies. Updated software measured strawberry conductivity at 121 frequencies between 100 Hz and 1 MHz to determine whether conductivity at these frequencies could differentiate ripeness, and be compared with the colour acceptance and stability of nectars produced from these strawberries.A high‐low ratio (HLR) was calculated by dividing the conductivity at frequency 1 MHz by conductivity at 1 kHz. HLR could be used to separate five strawberry ripeness stages, with decreasing HLR associated with increasing ripeness. HLR was then compared with the colour of nectars produced from these strawberries. Although there was a good correlation between HLR and an acceptable colour to consumers on initial production (r = −0.823, P < 0.001) and after 12 weeks of storage (−0.759, P < 0.001), cultivars differed greatly in both HLR and colour stability. Additionally, HLR had a strong correlation with firmness.The PEF Control System could be used to differentiate ripeness of strawberries by HLR, and therefore was associated with colour stability. However, no additional information on colour stability was gained from conductivity beyond what could already be deduced from differentiating ripeness based on surface colour. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Strawberry nectars have increased colour stability when produced from overripe, darker, and redder strawberries, with a high anthocyanin concentration. The post-harvest storage of strawberries has been shown to develop these properties. Nectars are frequently produced from strawberries rejected for fresh sale due to poor colour, which are insufficiently ripe to produce colour-stable nectars. This study investigated post-harvest anthocyanin development in strawberries to improve the colour and colour stability of nectars, which is the first time these developments were studied for beverage production. Strawberries at five ripeness stages were stored at 20 °C for 1 and 2 days prior to nectar production. The anthocyanin content of nectars was determined by a pH-differential method, and the colour stability was tracked for 12 weeks using a consumer Acceptance Factor, derived from CIELAB colour components. The anthocyanin content and colour stability were highly correlated, and both were dependent on ripening, with larger increases observed in under-ripe strawberries, and small to no improvement in overripe samples. Stored partially coloured strawberries produced nectars with equivalent colour stability to non-stored strawberries of normal ripeness. This allowed strawberries that were previously unsuitable for both fresh sale and nectar production to be used as a feedstock for nectar production, reducing food waste. [ABSTRACT FROM AUTHOR]