Near infrared reflectance of colored fruits.
The near ir (NIR) spectral properties of colored fruits were measured and showed a wide variation between species. Within a species, NIR reflectance was found to vary with the degree of ripeness of the fruit, particularly for the softer fruits. Extreme values of NIR reflectances were 75% for unripe pears and 21% for the red-ripe tomatoes. This variation is considerably larger than would have been expected from similar studies with leaves and grains. Solar reflectances were calculated for the NIR region for possible use in subsequent energy balance studies. Results from this study indicate that soft fruits will have a solar energy input 10-20% greater than for hard fruits, due to a 20-40% difference in NIR spectral properties. Softening accompanying ripening of tomatoes increases solar heat input by up to 10%.