*2.4. Respiration Measurements*

In experiment 2, respiration measurements were carried out according to method previously described by our group [30]. Analysis was carried out using an Interscience Compact GC system (Interscience, Breda, NL, USA) equipped with an RT-QBond column for detecting CO2 at the back channel and a MolSieve 5A coupled with a back pressure column type RT-QBond for the detection of O2 at the front channel. Helium with a constant pressure of 60 and 80 kPa was used as carrier gas for the back and front channel, respectively. Each column was connected to a Thermal Conductivity Detector (TCD) set at 110 ◦C. CGCeditor software (v1.5.5, 2008) was used to control the setting of the CompactGC. GC was continuously connected to the samples via tubing connected to a VICI valve (model EMTMA-CE). Valve and CompactGC were coordinated by EZChrom Elite software (v3.32 SP2).

Gas measurement were conducted directly from the container. Before measurement took place, the flow through the container was stopped to allow accumulation of CO2 and depletion of O2 and the first GC measurement was carried out. The second measurement was carried out at the end of the incubation period. The accumulation period was approximately 5 h. The difference in gas partial pressure between the first and second GC measurements was converted into consumption and production rates according to ideal gas law methods [31]. The measurement was carried out at day 4, 6, 10 and 12 during CA storage.

#### *2.5. Colour and Firmness Measurement*

Colour was assessed non-destructively by a hand-held photodiode array spectrophotometer (Pigment Analyzer PA1101, CP, Ibbenbüren, Germany). Remittance was assessed at 570 (R570) and 780 (R780) nm by calculating the normalised different vegetative index (*NDVI*, Equation (1)) and normalised anthocyanin index (*NAI*, Equation (2)) which are normalised value between −1 and 1 [32].

$$NDVI = \frac{R\_{780} - R\_{660}}{R\_{780} + R\_{660}} \tag{1}$$

$$NAI = \frac{R\_{780} - R\_{570}}{R\_{780} + R\_{570}} \tag{2}$$

Firmness was measured non-destructively using a commercial acoustic firmness tester (AFS, AWETA, Nootdorp, the Netherlands) with the tick power of the plunger set to 15. The AFS combines the single tomato resonant frequency (*f* in Hz) and mass (*m*, in kg), measured by an inbuild balance, into a *FI* (firmness index) [33] (Equation (3)).

$$FI = \frac{f^2 m^{2/3}}{10^4} \tag{3}$$
