Microph 2001 ph meter

Colour was measured by reflectance on sauce surface using a Chroma Meter II CR-200/08 (Minolta Ltd., Milton Keynes, UK) with a D65 illuminant, 2° observer angle and 50 mm aperture size. Results were expressed in CIE units: lightness (L*), redness (a*), yellowness (b*), and ΔE* [(L*_{day 0} − L*_{day 42})² + (a*_{day 0} − a*_{day 42})² + (b*_{day 0} − b*_{day 42})²]^1/2. The pH was determined with a MicropH 2001 pH meter (Crison, Barcelona, Spain) using a Cat. 52-22 combined electrode (Ingold Electrodes, Wilmington, DE, USA).

Fecal samples from the peri-inoculation period of the virus were diluted in distilled water (up to 200 mg/mL) and gently agitated. Their pH was measured using a 5207 pH electrode for surfaces (Crison Instruments, Barcelona, Spain) and a micropH 2001 pH meter (Crison Instruments).

For metabolomic analysis, apple and pear fruits were cut into halves and the true fruit parts (core and seeds) were removed using a small spoon (Schnitzmesser-set Professional; Triangle, Solingen, Germany). From each half, we prepared four equal pieces including the exocarp (skin) and mesocarp (pulp) using a professional tool for fruit sculpture (Schnitzmesser-set Professional). Two pieces were frozen in liquid nitrogen and stored at −80 °C as technical replicates. The other two pieces were frozen in liquid nitrogen and powdered using an A11 basic analytical mill (IKA-Werke, Staufen, Germany) and stored at −80 °C. For quality analysis, the °Brix, pH and hardness were determined for 30 fruits as previously described [14 (link)]. Briefly, the hardness was measured with a PCE-PTR 200N sclerometer (PCE Instruments, Lucca, Italy) at four fruit positions, then six pools of five fruits were created and the juices were extracted with a mixer. A micropH 2001pH meter (Crison, Carpi, Italy) and a DBR 35 digital refractometer (Kingstic, Ningbo, China) were used to assess the pH and °Brix, respectively.

pH was determined with a MicropH 2001 pH meter (Crison, Barcelona, Spain) and a Cat. 52-22 combined electrode (Ingold Electrodes, Wilmington, DE, USA). CIELab colour was measured using a CR-200/08 Chroma Meter II (Minolta Ltd., Milton Keynes, UK) with a D65 illuminant, 2° observer angle and 50-mm aperture size. The results were expressed as CIELab values: lightness (L*), redness (a*) and yellowness (b*).

Fecal samples from the peak of diarrhea (days 7–9) and from the end of the study (days 14–16) were diluted in distilled water (up to 200 mg/mL) and agitated, whereas stomach content samples from day eight and sixteen were measured directly without previous dilution. The measure of pH was performed using a 5207 pH electrode for surfaces and a micropH 2001 pH meter (Crison Instruments, Barcelona, Spain).