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Magistritöö Toiduainete tehnoloogia õppekaval Õlu on kääritatud alkohoolne jook, mida tarbitakse üle maailma. Traditsiooniliselt valmistatakse õlut gluteeni sisaldavatest odralinnastest, mis ei sobi tsöliaakiat põdevatele inimestele. Paraku on gluteenivabade toitude ja jookide valik piiratud. Tatar (Fagopyrum Mill.) on gluteenivaba taimeperekond tatraliste sugukonnas, millest tehtud õlu sarnaneb maitse, lõhna ja mõruduse poolest tavaõllele. Eestis toodavad gluteenivaba õlut vaid mõned tööstused ja väikesed pruulikojad. 100%-list tatraõlut Eestis ei toodeta ja tatart lisatakse enamasti maitselisandina. Antud magistritöö eesmärk oli uurida tatralinnastest tehtud meski filtreerimisvõimet virde eraldamisel ja virde kadu, et välja selgitada, kas tatart on optimaalne kasutada ainutoorainena, et toota gluteenivaba õlut. Selleks on katsetatud erinevate odra- ja tatralinnaste koguste vahekordadega ning uuritud virde saagist, et leida tatralinnase mõju virde omadustele. Toorainena olid kasutusel odralinnased „IREKS Pale Ale“ ning tatralinnased „Château Buckwheat“, lisanditeks maisihelbed, tatrakestad ja ensüümipreparaat Ceremix® Flex. Virdest määrati suhkrusisaldus, pH, erikaal, värvus EBC skaalal, erinevate süsivesikute sisaldus ja viskoossus. Rabast määrati niiskus- ja süsivesikute sisaldus. Samuti mõõdeti virde saagist liitrites. Tatralinnastega meskitud virde pH oli püsivalt üsna kõrge: leiti, et koguvirde pH (lisatud veega) on vahemikus 6,26-6,53, ja ilma lisatud veeta 6,16-6,45. Tatralinnaste osakaalu suurendamine tõstab virde pH-d, mis viitab nõrgale ensüümide toimele, selle vastu aitab mingil määral ensüümide lisamine, mis alandab koguvirde pH-d. Tatralinnase osakaalu tõstmine vähendas statistiliselt algvirde ja koguvirde suhkrusisaldust (r = -0,99, p = 0,002 ja r = -0,91, p = 0,034). 50, 75 ja 100%-lise tatravirde puhul suurendavad lisandid nagu maisihelbed ja ensüüm suhkrusisaldust. Tatrakestade kasutamine ei avaldanud märkimisväärset mõju. Kõige väiksem kaoprotsent saadi kasutades 50% tatralinnaseid ja 50% odralinnaseid, millesse oli lisatud ensüümipreparaati (8,6%). Üleüldine kaoprotsent kõikides katsetes jäi 9-24% vahele. Tatralinnaste osakaalul ja kao suurenemisel on tugev positiivne seos: r = 0,93, p < 0,05. Kadude vähenemisele aitab kaasa nii maisihelveste kui ka ensüümi lisamine, kusjuures on ensüümi lisamisel 100%- lise tatravirde kadu vaid ~17%. Maltoosisisaldus rabas vähenes tatralinnase suurema osakaaluga (r = -0,96, p < 0,05), kusjuures 100%-lise tatravirde puhul puudus maltoos täielikult. Maltoosisisalduse parandamiseks kasutati ensüümipreparaati, mis tõstis maltoosisisalduse 9,43%-ni. Tulemustest selgus, et gluteenivaba 100%-list tatraõlut on võimalik pruulida ainult sel juhul, kui meskimisel kasutada ensüümipreparaati. 75%-list tatraõlut saab pruulida ilma ensüümita, kuid esinevad maitse-, lõhna- ja viskoossusevead. Virde omadused sõltuvad suuresti meskimisparameetritest, seega oleks tatralinnaste filtreerimisvõime ja virde saagise täpsemaks hindamiseks tarvis läbi viia veel täiendavaid uurimusi, kasutades kirjanduses leiduvaid optimaalsemaid meskimisparameetreid, mis võiksid suurendada virde suhkrusisaldust ja saagist. Beer is a fermented alcoholic beverage that is consumed around the world. It is traditionally brewed from gluten-rich barley malt, which is not suitable for people with coeliac disease. Unfortunately, the variety of gluten-free foods and beverages is limited. Buckwheat (Fagopyrum Mill.) is a gluten-free plant in the Polygonaceae family, the beer of which is similar in taste, aroma and bitterness to ordinary beer made from barley. Only a few industries and small breweries produce gluten-free beer in Estonia. Beer made only from buckwheat is not produced in Estonia, and when it is buckwheat is usually added as an adjunct. The aim of this master’s thesis was to study the filtration capacity of buckwheat mash during the separation of wort from brewers’ spent grain (BSG) and the loss of wort, to find out whether buckwheat can be used optimally as a sole raw material to produce gluten-free beer. To this end, different ratios of barley and buckwheat malt were used, and the yield of wort was examined, to characterise the effect of buckwheat on the quality of wort. The raw materials used were barley malt “IREKS Pale Ale” and buckwheat malt “Château Buckwheat”, with the addition of cornflakes, buckwheat husks and Ceremix® Flex enzyme. The sugar content, pH, specific gravity, colour in EBC units, content of carbohydrates and viscosity were measured from wort. Moisture content and the content of carbohydrates were measured from BSG. The yield of wort was measured in litres. The pH of buckwheat wort was consistently quite high: the pH of wort (with added water during filtration) was found to be in the range of 6.26-6.53, and without added water 6.16-6.45. Increasing the proportion of buckwheat malt raised the pH of the wort, which indicates little enzymatic activity, while the addition of enzymes helped to some extent, and lowered the pH of the wort. Increasing the proportion of buckwheat malt statistically reduced the sugar content of the initial and total wort (r = -0.99, p = 0.002 and r = -0.91, p = 0.034). For mash with 50, 75 and 100% buckwheat malt, additives such as cornflakes and enzymes increased the sugar content of wort. The use of buckwheat husks did not have a significant effect. The highest yield (91,4%) was obtained using 50% buckwheat malt and 50% barley malt with added enzymes. The overall loss rate in all experiments ranged from 9% to 24%. There was a statistically strong relationship between the proportion of buckwheat malt and the increase of losses: r = 0.93, p < 0.05. The addition of both cornflakes and enzymes contributed to the reduction of losses, whereas the addition of enzymes resulted in a loss of only ~17% of wort made solely from buckwheat. The maltose content in BSG decreased with a higher proportion of buckwheat malt (r = -0.96, p < 0.05), whereas maltose was completely absent in the case of 100% buckwheat BSG. For this, an enzyme was used to improve the maltose content, which increased it to 9.43%. The results showed that gluten-free beer made solely from buckwheat malt can only be brewed if an enzyme preparation is used in the brewing process. Beer made with 75% of buckwheat malt can be brewed without added enzymes, but there are defects of taste, smell and viscosity. The properties of the wort depend largely on the parameters of mashing, so further studies would be needed to better assess the filtration capacity of buckwheat mash and the yield of wort, using more optimal mashing techniques, as proposed in the literature. |
