Modulating temperature and pH during subcritical water extraction tunes the molecular properties of apple pomace pectin as food gels and emulsifiersShow others and affiliations
2023 (English)In: Food Hydrocolloids, ISSN 0268-005X, E-ISSN 1873-7137, Vol. 145, article id 109148Article in journal (Refereed) Published
Abstract [en]
This study explores the cascade extraction of polyphenols and pectins from apple pomace and their potential application as food emulsifiers. The extraction of polyphenols was achieved by a simple method using ethanol and resulted in remarkable antioxidant activity. Pectic polysaccharides were sequentially extracted (5, 10 and 15 min) using subcritical water at two different temperatures (120 °C and 140 °C) and three different pH conditions (pH 3.0, 5.0 and 7.0). Acidic pH resulted in higher pectin yields when combined with higher temperature, whereas neutral conditions were less selective towards pectin. Pectin with different branching patterns could be isolated by tuning the process conditions. Linear homogalacturonan (HG) was preferentially isolated at milder conditions, whereas more branched rhamnogalacturonan (RG-I) populations required longer extraction times. Subcritical water enabled the extraction of pectins with different degrees of methoxylation (DM) depending on the extraction pH, which enabled the production of pectin acid gels with varying rheological properties. Low DM pectin was directly recovered from apple pomace at lower pH, eliminating the need for its conventional derivatization from high DM pectin. The emulsifying properties of two apple pomace pectin fractions with high and low methoxyl content were compared; the pectin with higher methoxyl content showed higher emulsifying capacity and stability. This study demonstrates that the relative abundance of the different pectic domains and the methoxylation of pectin can be controlled by subcritical water extraction, which has important implications for the valorization of pectic-rich agricultural wastes into valuable food ingredients. © 2023 The Authors
Place, publisher, year, edition, pages
Elsevier B.V. , 2023. Vol. 145, article id 109148
Keywords [en]
Apple pomace, Emulsifier, Food waste, Gelling properties, Pectin, Subcritical water, Agricultural wastes, Emulsification, Fruits, Gels, Degree of methoxylation, Modulating temperature, Polyphenols, Sub-critical water, Subcritical water extraction, Extraction
National Category
Food Science
Identifiers
URN: urn:nbn:se:ri:diva-65975DOI: 10.1016/j.foodhyd.2023.109148Scopus ID: 2-s2.0-85166971471OAI: oai:DiVA.org:ri-65975DiVA, id: diva2:1790584
Note
The authors acknowledge Isadora Spoerer and Francisco Zamudio (Väddö Musteri, Grisslehamn, Sweden) for providing the apple pomace. FV acknowledges the Swedish Research Council Formas (Project 942-2016-119 and Project 2020–01575 ) for financial support
2023-08-232023-08-232023-08-23Bibliographically approved