FOODBALT 2014 BERRY AND FRUIT JUICES AS POTENTIAL UNTRADITIONAL ACIDITY REGULATORS IN MASHING Ingmars Cinkmanis, Sanita Vucane, Ilze Cakste Department of Chemistry, Faculty of Food Technology, Latvia University of Agriculture, Liela street 2, Jelgava, Latvia, e-mail: [email protected] Abstract Acids traditionally used for acidification of mash (lactic acid, phosphorus acid) provide optimal medium pH, however, it is theoretically possible to choose such agents that would complete several tasks, ensuring the regulation of pH. Berry and fruit juices (cranberry, black currant, red currant, quince, apple and lemon) containing different organic acids, such as citric acid, malic acid, tartaric acid and fumaric acid, have similar properties, although they can not only acidify mash but also increase the content of extract substances in wort. In berries and fruits juices titratable acidity and pH was measured potentiometrically using pH meter. The highest titratable acidity of berry and fruit juices was in lemon (5.71 mmol L-1) and quinic juice (5.80 mmol L-1). Lemon juice has a lower pH 2.40 and apple juice has the highest pH 4.82. Results of the analysis of mash pH changes showed, that it is possible to reduce pH replacing traditional acidification regulators (lactic acid, phosphoric acid) with berry and fruit juices. The pH was practically in all the mashing stages in the limits of 5.14±0.02 up to 5.19±0.02. The content of wort extract was analyzed using beer analysing system – Anton Paar „Alcolaizer” analysis. Using HPLC the Carbohydrates like glucose and maltose in wort were detected and quantified. The optimal berry and fruit mashing acidification regulators were quince and cranberry juices. Keywords: acidity regulators, pH, mashing, mash, wort. Introduction extracted in juice extractor Moulinex A7534K, and pasteurized 80 °C, 1.5 L min-1 with Voran PA 90. In brewing, the raw materials that give the beer its Chemical acidity regulator reagents: lactic, specific sensory properties are water, barley malt, hop, phosphoric, fumaric, quinic, malic and citric acids and yeast. The most important technological process in HPLC–grade>99.0% (Fluka, Germany) producing of wort is the mashing what is the first stage An amount of acidity regulators (Fig. 1.) added to of beer preparing (Heyse, 1995., Kunze, 1998). The experimental mash with initial pH. factors that affect the output of malt extract are the quality of water, medium pH and temperature. In the process of mashing, it is important to provide the 2.50 2.20 optimal conditions for starch hydrolysis ferments 1 2.00 α-amylase and β-amylase activity. The largest - 1.50 α-amylase activity was stated when medium pH was 1.50 1.30 1.20 5.1–5.2. In the mashing process mash pH is higher and 1.00 optimal pH is obtained by adding traditional 1.00 0.80 acidificators: phosphor acid, lactic acid or gypsum to 0.50 0.50 the mixture (Kunze, 1998; Narziβ, 2004; Meледина et mL L Volume, 0.50 al., 2006). However, these traditional materials can be 0.00 partially replaced with other products. Berry and fruit P F U J Cit Cid Dz A juices (cranberry, black currant, red currant, quince, Acidity regulators apple and lemon) containing different organic acids, such as citric acid, malic acid, tartaric acid and fumaric Figure. 1. An amount of added acidity acid, have similar properties, although they can not regulators in mash only acidify mash but also increase the content of P – lactic acid, F – phosphoric acid, U – black currants juice, extract substances in wort. J – red currants juice, Cit – lemon juice, Cid – quinice juice, The aim of the research was to produce the wort using Dz – cranberries juice, A – apple juice untraditional acidity regulators as fruit and berry juices and to analyse its chemical composition. Raw materials of mashing Light barley malt (Brupak, England), water (SIA Materials and Methods „Griģis un Co”) in accordance with the law of LR MK Acidity regulators Nr.235/29.04.2003. Samples of berry and fruit: (black currant (Ribes The titratable acidity and pH nigrum), red currant (Ribes rubrum), quince (Cydonia The titratable acidity and pH was measured oblonga), cranberry (Vaccinium microcarpum), apple potentiometrically using pH meter – WTW inoLab® (Antonovka) (Malus sylvestris) were collected at Cesis pH 720. region in Latvia. Lemon juice is obtained from Lemon samples (Citrus х lemon) buy in local retail market Wort extract Maxima. After collection, the berries and fruits were Content of wort extract was analysed using beer analysing system - Anton Paar „Alcolaizer analysis”. 184 FOODBALT 2014 Carbohydrates It should be concluded from the data presented in The Carbohydrates was determined by HPLC using Figure 3, that from the berry and fruit juices the lemon Shimadzu LC20 Prominence chromatographer. juice has a lower pH 2.40 and apple juice has the Determination parameters: Refractive Index Detection highest pH 4.82. The total titratable acidity of berry and fruit juices are RID-10A; Column: Alltech NH2, 4.6x250mm, 5μm; Temperature of the column: +30 °C; Mobile phase: A – showed in Figure 4. acetonitrile and water (70:30); Isocratical regime; 7.00 Capacity of the injection sample; 10 μL; Rate of the 5.71 5.80 6.00 flow: 1.3 mL min-1; Total time of the analysis: up to 5.00 1 20 minutes. - Technological process of mashing and obtaining wort 4.00 2.70 3.01 3.00 (Fig.2.) 1.90 2.22 mmol L mmol 2.00 1) Water (t=37 °C) (1 L) mixed with light acidity, Titratable 1.00 malt (0.2 kg) pH of Mash 6.20 and acidificated to pH 5.20 0.00 A U Dz J Cid Cit with: 1) Lactic or phosphoric acid Berry and fruit juices 2) Fumaric, quinic, malic or citric acid Figure 4. The titretable acidity of berry and fruit juices 2) Mashing: U – black currants juice, J – red currants juice, a) Mashing-in (τ=20 min, t=35 °C) Cit – lemon juice, Cid – quinice juice, Dz – cranberries juice, b) Protein pause (τ=25 min, t=55 °C) A – apple juice c) Maltose pause (τ=40 min t= 65 °C) d) Dextrine pause (τ=40 min, t=72 °C) The highest titratable acidity of berry and fruit juices -1 was in lemon (5.71 mmol L ) and quinic juice -1 (5.80 mmol L ). Mash filtration Changes of pH in mashing process and evaluation of (τ=15 min) extract substance content It is possible to reduce pH mash during mashing using cranberry, black currant, red currant, quince, apple, Wort boiling lemon fruit and berry juices up to pH 5.20±0.02. The (τ=90 min, t=100 °C) changes of mash pH by fruit and berry juices are slight and vary between 5.19±0.02 and 5.14±0.02, thus providing amylase activity of α- and β-enzymes and Figure. 2. Technological process of preparation optimal conditions for starch hydrolysis (Kunze, 1998, mash and wort Montanari et al., 2005). The content of measured extract substances in wort Mathematical data processing obtained during the experiments using traditional and Data obtained were analysed using statistical software untraditional acidity regulators is displayed in Fig. 5. Minitab 15 for Windows. 14 12.0 12.5 12.5 12 10.7 Results and Discussion 10.5 10.0 9.9 10.6 10 The titratable acidity and pH of berry and fruit juices. ° The pH in the samples is characterized in Figure 3. 8 Er, PlEr, 6 6 4 4.68 4.82 5 4.34 4.45 2 3.66 4 0 P F U J Cit Cid Dz A pH 3 2.40 2 Acidity regulators 1 Figure. 5. The content of extract substances in wort 0 (Er), using various acidity regulators Cit Cid Dz J U A U–black currants juice, J–red currants juice, Cit–lemon juice, Ci–quinice juice, Dz–cranberries juice, A–apple juice Berry and fruit juices Figure. 3. The pH of berry and fruit juices Optimal results of extract substances are gained using U–black currants juice, J–red currants juice, Cit–lemon juice, cranberry (12.5 Pl°) and quince (12.5 Pl°) juices, the Cid–quinice juice, Dz–cranberries juice, A–apple juice lowest results – using red currant 9.9 (Pl°) and black 185 FOODBALT 2014 currant juices. The obtained results using traditional Content of carbohydrates in the wort acidity regulators, lactic acid and phosphorus acid, are Starch in malt hydrolyses to dextrin in mashing process 12.0 Pl° and 10.5 Pl° (Fig. 5.). Comparing quinic and where enzymes α- and β-amylases are active, thus cranberries juices to the traditional acidity regulators forming maltose and glucose. The amount of maltose lactic acid, the quinic and cranberries juice’s and glucose in wort depends on mashing conditions acquisition of extract substances is more efficient by and certain organic acid used for acidification. 0.5 Pl°. Using lemon, apple, black currant and red Measured content of carbohydrates is displayed in currant juices for acidification of mash there were Table 1 and 2. fewer amounts (by 14.4–23.2%) of extract substances extracted comparing to cranberry and quince juices. Table 1 Content of carbohydrates in the wort, % Acidity regulators Carbohydrate P F U J (n=5) x i ±SD% (n=5) i ±SD% (n=5) i ±SD% (n=5) i ±SD% Fructose – – 0.13±0.05 0.11±0.05 Glucose 1.36±0.03 1.17±0.03 1.08±0.03 0.91±0.03 Sucrose 0.40±0.06 0.34±0.06 0.32±0.06 0.26±0.06 Maltose 7.38±0.05 6.30±0.05 5.83±0.05 4.91±0.05 P – lactic acid, F – phosphoric acid, U – black currants juice, J – currants juice Table 2 Content of carbohydrates in the wort, % Acidity regulators Carbohydrate Cit Cid Dz A (n=5) i ±SD% (n=5) i ±SD% (n=5) i ±SD% (n=5) i ±SD% Fructose 0.08±0.05 0.07±0.05 0.07±0.05 0.11±0.05 Glucose 1.19±0.03 1.35±0.03 1.37±0.03 1.00±0.03 Sucrose 0.34±0.06 0.39±0.06 0.37±0.06 0.54±0.06 Maltose 6.50±0.05 7.42±0.05 7.44±0.05 7.46±0.05 Cit–lemon juice, Cid–quinic juice, Dz–cranberries juice, A–apple juice As the amount of extract substances is different when glucose and fructose is arranged as follows: black using various acidity regulators in mashing process currant (8.09%) > red currant (7.64%) > apple (4.10%) (Fig.