Kate P. Perry

The aim of this study was to investigate the effects of thermo-maceration and apple pomace addition on phenolic compound extraction during cider fermentation and on the volatile profile of the final product. Jonagold apples were milled, and the juice was divided into four groups: (1) Control: no apple pomace or thermo-maceration; (2) Control TM: thermo-maceration only; (3) CiderAP: apple pomace addition only; and (4) CiderAPTM: apple pomace addition combined with thermo-maceration. Apple pomace was added at 50% of the average pomace weight created during milling, and thermo-maceration consisted of heating the juice to 60 °C for 1 h prior to fermentation. Ciders were fermented at 20 ± 1 °C for 14 days. CiderAP and CiderAPTM showed higher total phenolic content (TPC) and antioxidant activity than the control treatments. The volatile profile was also modified, with CiderAPTM showing the highest phenylethyl alcohol concentration and esters exhibiting compound-specific responses. Statistical analysis showed that only apple pomace addition significantly increased TPC and antioxidant activity, while both apple pomace addition and thermo-maceration affected the volatile profile. Under the conditions evaluated, thermo-maceration did not increase TPC or antioxidant activity beyond the effect of apple pomace addition but did modify the volatile profile of the ciders. Further research should evaluate different thermo-maceration temperatures and durations to determine its potential application in cider production. The findings of this study provide valuable insights for cider makers on the valorization of apple pomace and potential use of thermo-maceration in cider production.

The quality of cider is influenced by its phenolic compound content. Apple pomace, an industrial by-product of cider production, is rich in bioactive compounds, including polyphenols. The objective of this study was to determine the potential of apple pomace addition during fermentation to increase the phenolic content in cider. Apple juice from Jonagold apples was divided into a control and three treatment groups. Control cider was fermented with 100% apple juice, while treatments were prepared with different additions of apple pomace to the apple juice. Ciders were fermented for 14 days, followed by chemical and sensory analysis. Ciders with apple pomace addition contained 31–61% higher phenolic compound concentrations than the control. The addition of apple pomace modified the volatile profile of the ciders. Treatment ciders contained higher concentrations of isoamyl alcohol, phenylethyl alcohol, and ethyl acetate, and lower concentrations of acetaldehyde. Ciders with apple pomace addition exhibited lower levels of astringency and sourness, and higher bitterness levels compared to the control. There was no difference in aroma perception and taste acceptance between the ciders. This study demonstrates the potential of apple pomace addition as a cidermaking technique for phenolic compound extraction and sensory profile modification.