Addition of Malvasia di Candia Aromatica must and marcs to Golden Ale beer wort to obtain different Italian Grape Ales

Abstract

Nowadays, the recovery of secondary resources of wine industry is insufficient and the developing of new products and adjuvants from secondary raw materials could become a relevant sector of research. The re-use of byproducts derived from winemaking could improve the sustainability of wine industry and give additional value to other food industries. In the last decades the number of craft breweries have significantly grown all over the world and food market saturation with new food products seemed to be at an all-time high, including alcoholic beverages. For this reason, many breweries started to produce non-conventional beers, also using different raw materials such as ancient grains, spices, and fruits, trying to put on the market something that previously did not exist. Italian Grape Ale (IGA) beers are produced starting from pils or pale malt and should not exhibit a roasty, stout like, profile. Grape or grape must can be pasteurized before the addition and used at different stages of brewing boil, primary/secondary fermentation, or aging. The addition can range from 5% to 40 % of the wort composition. A proper option for brewers could be the addition of an aromatic grape variety to beer wort. Malvasia di Candia aromatica (MaCA) is a grapevine (Vitis vinifera L.) cultivar (cv.) that produces aromatic white grapes and is mainly cultivated in the Emilia Romagna province of Piacenza. Another possibility to make new products in beer industry is related to grape marcs addition in different stages of the brewing process with a high added value from a chemical and nutritional point of view. This work studied the possible addition of MaCA grape must and marcs to Golden Ale beer wort in different percentages: 10 and 20%. Fermentations were carried out in triplicate with a control made of 100% beer wort. General parameters, organic acids (LC-DAD), aroma compounds (GC-MS), target polyphenols (LC-MS/MS) and sensory evaluation were carried out to evaluate changes after MaCA juice and marcs addition. Increasing in acidity values were measured in final products after MaCA juice addition compared to controls (1.98, 2.31, and 2.41 g/L of tartaric acid equivalent in beer controls, MaCA 10%, and MaCA 20%, respectively) and after MaCA marcs addition (1.98, 3.15, and 3.40 g/L of tartaric acid equivalent in beer controls, MaCA 10%, and MaCA 20%, respectively). Other results confirmed that beers with 20% MaCA juice addition and 10% MaCA marcs addition resulted more complex in aroma profile with the presence of free monoterpenic compounds, expecially β-citronellol, linalool, linalool oxides, nerol and α-terpineol. Sensory evaluation confirmed differences in aroma intensity and acidity perception between different beers. Panelists preferred the addition of 20 % of MaCA juice as the best option. Collaboration with a craft brewery will carried out to produce beers with addition of 20 % of MaCA juice and 10% of MaCA marcs in a 12-hL scale.