Effect of Extraction Conditions for Recovery of Chlorogenic Acid and Flavonoids from Wet Cider Apple Pomace under Subcritical Water

Salis Ibrahim,Regina Santos,Steve Bowra

doi:10.5539/jfr.v8n6p1

Abstract

Industrial wet cider apple pomace was subjected to subcritical water mediated hydrolysis in a batch reactor with varying experimental conditions such as solid-to- solvent ratio (1-8 % w/v), temperature (100- 200 oC) and a residency time (10-30 min) to understand the effects of the experimental conditions on overall recovery of polyphenolic compounds. Chlorogenic acid and some flavonoids were identified and quantified by high performance liquid chromatography (HPLC-DAD). Higher yields of chlorogenic acid and the flavonoids were obtained between 100- 150 oC for residence time of 20 minutes. Solid-to solvent ratio and temperature played a significant role in the recovery of the polyphenolic compounds (p&lt; 0.05). The results demonstrated that, residence time at a fixed extraction condition was less significant (p&gt; 0.05). However, it was significant for yield of degradation compounds such as protocatechuic aldehyde, 5- HMF and furfural. Subcritical water selectively influenced the chemical structure of the polyphenolic compounds.

Highlights

Apples (Malus domestica) are extensively cultivated in many moderate temperate regions of the world
Industrial wet cider apple pomace was subjected to subcritical water mediated hydrolysis in a batch reactor with varying experimental conditions such as solid-to- solvent ratio (1-8 % w/v), temperature (100- 200 oC) and a residency time (10-30 min) to understand the effects of the experimental conditions on overall recovery of polyphenolic compounds
Solid-to solvent ratio and temperature played a significant role in the recovery of the polyphenolic compounds (p< 0.05)

Summary

Introduction

Apples (Malus domestica) are extensively cultivated in many moderate temperate regions of the world. Apples can be categorised into, culinary, desert and cider apple varieties. Apple pomace is the residue generated after juice extraction and is composed of 20- 35% by weight of the original production feedstock. The amount of the pomace generated and its composition will depend on the variety of the apple and the techniques used in extracting the juice (Mahawar et al, 2012). 9 × 106 tonnes of apple pomace are produced worldwide per the estimation of the amount of apples processed. China is the largest producer of apple pomace in the world with estimated annual yield of over 3 million tons since 2009 (Yue et al, 2012). In northern Spain, 20,000 tonnes per annum of the pomace is generated and accounts for a significant proportion of the global cider apples production (Diñeiro García et al, 2009). Apple pomace is a heterogeneous biomass residue consisting of peels, discarded apples, seeds, core, stems and exhausted apple tissue and a potential source of carbohydrate, fibre, polyphenolic compounds and pectin which can serve as valuable feedstock for food, feed, pharmaceutical or http://jfr.ccsenet.org

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