Electrical bioimpedance and mechanical penetrometry test for remotely detecting the tissue damage due to mis-management of the cold chain in oblong red chicory

Abstract

The oblong red chicory (Cichorium intybus) is a vegetable of considerable value since it is rich in water and low in calories (just 18 kCal per 100g) and the higher fibre content could provide of satiety during the meal. Moreover, such fibres are rich in inulin which is capable of positively selecting our intestinal microbiota. However, due to the limited diffusion of territories for its cultivation oblong red chicory may be subject to conservation along a specific cold chain to delay them for as long as possible biological processes of maturation, but low-temperature could cause internal breakdown that may limit the time in which this vegetable can be held and still ripened normally. In this experiment a suitable quantity of this vegetable was subjected for12 hours temperatures stages respectively at -2°C, -8°C and -18°C, while 7°C was chosen as control temperature. After a thawing period, electrical bioimpedance and mechanical penetrometry measurements, i.e. the gold standard test but tricky to use, were applied to the chicory samples. Results showed that, as freezing temperature fell, at each unitary mechanical pressure change (1 kg cm-2) electrical impedance directly changed of about 18 Ω (linear regression test: P=0.018). So electrical bioimpedence measurements could be a new and easily method to control possible mis-management of the cold chain in logistic processing of the oblong red chicory.