From Byproduct to Resource: Fermented Apple Pomace as Beer Flavoring.

Annalisa Ricci,Martina Cirlini,Camilla Lazzi,Claudia Liberatore,Tommaso Ganino,Benedetta Chiancone,Angela Guido

doi:10.3390/foods8080309

Abstract

One of the main struggles of the large-scale apple processing industry is pomace disposal. One solution for this problem is to convert this waste into a resource. Apple pomace could be used as a substrate for lactic acid bacteria and could induce the formation of a more complex aroma profile, making this fermented product an innovative aromatizer for alcoholic beverages, such as beer. In this study, for the first time, the effect of lacto-fermented apple pomace addition in beer was evaluated. Three bacterial strains (Lactobacillus rhamnosus 1473 and 1019, and L. casei 2246) were tested for apple pomace fermentation, and L. rhamnosus 1473 was the strain that best modified the aromatic profile. The addition of fermented apple pomace to beer increased the complexity of the aroma profile, demonstrating the potential of this byproduct as an aromatizer in the alcoholic beverage industry.

Highlights

With almost 90 million tons produced all over the world in 2016, apple (Malus domestica Borkh.)is one of the most cultivated fruit crops [1], and it can be consumed fresh or as juice, cider, wine, and vermouth, purees, jams, and dried products [2].The apple transformation industry generates large amounts of waste known as ‘apple pomace’(3600 ktons in 2010), which is mainly composed of skin and flesh (95%), seeds (2% to 4%), and stems (1%) [3]
Three different strains belonging to L. rhamnosus (1473 and 1019) and L. casei (2246) species were employed
Fungi and yeast have been previously used for apple pomace fermentation, producing different compounds such as enzymes [6], citric acid [9], and animal feed [10]

Summary

Introduction

With almost 90 million tons produced all over the world in 2016, apple (Malus domestica Borkh.)is one of the most cultivated fruit crops [1], and it can be consumed fresh or as juice, cider, wine, and vermouth, purees, jams, and dried products [2].The apple transformation industry generates large amounts of waste known as ‘apple pomace’(3600 ktons in 2010), which is mainly composed of skin and flesh (95%), seeds (2% to 4%), and stems (1%) [3]. The apple transformation industry generates large amounts of waste known as ‘apple pomace’. For the large-scale apple processing industry, pomace disposal is a big problem, impacting massively on the environment; for this reason, in recent years, many efforts have been made to convert this waste into a resource, exploiting its richness in nutrients. Apple pomace composition varies depending on the variety, origin, and processing technology prior to its generation, but in general, it contains 70% water, 16% carbohydrates, 7% cellulose, 5% protein [4], and many valuable polyphenols with antioxidant properties [5]. Apple pomace waste is an excellent resource for the production of various chemical compounds, such as pectin, limonene, and d-galacturonic acid [7]; thanks to its abundance of fermentable soluble sugars, including glucose, apple pomace is a perfect substrate for fermentative processes

Methods

Results

Conclusion