ABSTRACT The objective of this study was to investigate the influence of ultra‐high pressure homogenization UHPH, 0 MPa (Control without UHPH), 100, and 150 MPa and different enzyme treatments (non‐enzyme, pectinase and cellulase) on some quality and color changes of fruit juices produced from dried apple pomace powder (DAPP). DAPP was a valuable waste product due to its high total phenolic content (198.42 ± 2.60 mg GAE/100 g dw) as well as low moisture (2.78 ± 0.17%) and pH (3.20 ± 0.03). The pH, total soluble solids (TSS), color, total color difference (Δ E ), and National Bureau of Standards (NBS) parameters of fruit juices (DAPPJ) produced from DAPP were affected by both enzyme ( p < 0.01) and UHPH treatments ( p < 0.01). Enzyme and UHPH treatments increased the TSS value ( p < 0.05). Pectinase treatment of DAPPJ resulted in lower pH values and color coordinates ( L *, a *, and b *) compared to cellulase and non‐enzyme groups ( p < 0.05). Regardless of enzyme treatment, UHPH processing increased lightness and yellowness, while decreasing redness in DAPPJ. The combination of pectinase enzyme and 100 MPa UHPH offered a ‘distinct’ color difference with the lowest Δ E , while Δ E was ‘very distinct’ in all treatment groups processed with 150 MPa UHPH ( p < 0.05). The color difference based on NBS classification was “noticeable” for enzyme treatments and “appreciable” for UHPH processing. Considering a lighter yellowish and less reddish fruit juice for consumer acceptance, the combination of cellulase enzyme and 150 MPa UHPH can be recommended for industrial applications of DAPPJ. On the other hand, to minimize the visible color difference, a combination of pectinase enzyme and 100 MPa UHPH is a more suitable option for DAPPJ production.
Aksu et al. (Sun,) studied this question.