A freshness index for bell pepper fruit

Freshness provides the appeal for the consumer to purchase a particular horticultural produce.
Freshness is a combination of size, colour, shape, flesh firmness, turgescence and glossiness without wilting, which imply that the produce has been harvested only a short time ago and has not suffered any decay during harvest, transport or storage.
The objective of the present work was to develop a freshness index based on non-invasive, real-time measurements, using changes in surface appearance after harvest on bell pepper as the most difficult model fruit.
Fruit glossiness was measured non-destructively using a luster sensor (type CZ-H72 from Keyence Co., Osaka, Japan). Luster values in excess of 463 (until 565) a.u. were classified as fresh.
This freshness index dropped, indicating a lesser freshness, to less than 100 a.i. after 14 days storage, irrespective of fruit colour, thereby providing a suitable wide, ca. 5-fold, range of parameterization.
The difference between the light reflectance peaks at 630 nm and at 500 nm, also measured perpendicular to the convex fruit side, decreased from > with fresh red and yellow bell pepper to ca. 20% after 14 days storage, and from ca. 16 to ca. 8% in green pepper fruit, in both cases by ca. 2-fold.
A freshness index >10 is suggested as a combination of luster values larger than 470 a.u. and >40% difference of the light reflectance between 630 and 500 nm as fresh bell pepper fruit.

XXXI International Horticultural Congress (IHC2022): International Symposium on Integrative Approaches to Product Quality in Fruits and Vegetables

B. Althaus, M. Blanke

pepper (Capsicum annuum L.), freshness, fruit quality, glossiness, index, non-invasive technique, shrivel, sustainability, turgescence, wilting

https://doi.org/10.17660/ActaHortic.2022.1353.10