Increased Temperature Effects During Fruit Growth and Maturation on the Fruit Quality, Sensory and Antioxidant Properties of Raspberry (Rubus idaeus L.) cv. Heritage

Red raspberries are valued for their color, flavor, and health-promoting organic compounds, which may be affected by increased temperatures due to climate change. This work aimed to provide new information on the response of raspberry cv. "Heritage" to thermal increase and its impact on fruit quality and perceived flavor. The study was conducted during two seasons in two locations with contrasting agroclimatic conditions. A zone with high background temperatures (central orchard) and low background temperatures (southern orchard) were studied. The treatments were three heating chambers installed at the fruit set, increasing the ambient temperature by ~4 °C, and untreated controls. Heat-treated raspberries were larger than the controls but showed softer fruit. Soluble solids were lower in treated fruit, while titratable acidity did not show a consistent pattern between treatments or orchards. Flavonoid content and anthocyanins did not present a clear pattern for both orchards and seasons. Heated raspberries had lower vitamin C in both years and orchards. The sensory analysis revealed differences only in color uniformity in the heated fruit from the central zone. Increased temperatures will affect the quality and nutritional aspects of the raspberries; however, at a sensory level, these changes may not be perceived.