Reshaping Apple Juice Production Into a Zero Discharge Biorefinery Process

Abstract

In the last decade, the utilization of waste by-product apple pomace has been extensively researched (due to its difficult disposal) and currently finds beneficial usage in various industries; as substrate for microbial growth or recovery of pectin, xyloglucan and polyphenols. In this research apple juice was produced at pilot scale. Furthermore, apple pomace was employed as substrate for the production of pectin, biofuel (pellets) and concentrated apple pomace extract. Extensive mass and heat balances were conducted to evaluate the feasibility of this approach on industrial scale. The produced pellets had very similar characteristics to wood pellets (net calorific value of 20.3 MJ/kg). Dried apple pomace contained 11.9% of pectin. Fed-batch cultivation of baker´s yeast with apple pomace extract demonstrated a potential for partial substitution of molasses in industrial bioprocesses. This concept shows how a zero discharge biorefinery process converts waste from apple juice production into three valuable products enabling connections between different industries. Graphic Abstract

Sustainable valorization of apple waste in a biorefinery: a bibliometric analysis

“…Then, the production of pectin presents a developed TRL with demonstration technology for industrial implementation. The use of apple pomace as feedstock for pectin recovery in a biorefinery can be an alternative to decrease the amount of by‐products generated in this industrial sector 21 . For the complete implementation of an apple biorefinery, effective stakeholder engagement between academia and industry is necessary.…”

“…In the case of apple juice, approximately 17 × 10 6 kg were exported from Brazil in 2017, accounting for an income of US$ 19 270 369 20 . Hence, the generation of apple pomace from juice production in Brazil has been estimated at 1 375 000 tons 21 . The industrial step for juice production can be summarized as reception, storage, washing, sorting (to remove twigs and rotten fruit), disintegration (by chopping or milling) and juice extraction (by hydraulic processing or enzymes).…”

Agricultural Residues as a Source of Bioactive Substances—Waste Management with the Idea of Circular Economy

“…Based on these facts, it can be calculated that probably about 500,000 tons of apple pomace were generated in Poland in 2018. For comparison, a neighboring country (Germany) produces half as much apple pomace (250,000 tons per year) [13].…”

Sustainable Use of Apple Pomace (AP) in Different Industrial Sectors

“…Based on these facts, it can be calculated that about 0.5 million tons of AP were generated in Poland in 2018. For comparison, a neighbouring country, Germany, produces half as much AP (0.25 million tons/year) [ 20 ]. The literature shows that the largest apple producer, China, generates more than one million tons of apple pomace annually [ 21 ].…”

“…The literature shows that the largest apple producer, China, generates more than one million tons of apple pomace annually [ 21 ]. Countries such as New Zealand, Spain and Brazil are characterised by small amounts of generated apple juice by-products (from about 20,000 to 13,750 tons per year) [ 20 ]. Global apple production has reached over 87 million tons/year, resulting in 3.915–4.698 million AP (in 2019).…”