Marchal Richard, Lallement Armelle, Jeandet Philippe, Establet Gérard
Laboratoire d'oenologie, Université de Reims, URVVC, B.P. 1039, 51687 Reims Cedex 2, France.
J Agric Food Chem. 2003 Mar 26;51(7):2040-8. doi: 10.1021/jf0207833.
The bovine spongiform encephalopathy (BSE, mad cow) crisis has led some wine-makers to question gelatin as a fining agent and to reject the use of these animal proteins. The search for a substitute for gelatin was begun by comparing vegetable proteins (particularly gluten) with gelatin fining treatments. Clairette de Die (French-controlled appellation) is a sparkling sweet wine. The alcoholic fermentation begins in a tank, continues in a crown-cap bottle, and stops before the complete consumption of sugar. All particles present in the bottle have to be removed before corking, and it is important to have a must as clear as possible. This study concerned the clarifying of a Muscat must, treated with pectinases, using a very efficient flotation technique. The must is fined with bentonite/silica/protein (fish gelatin, wheat gluten, or lupin isolate) to induce flocculation and then pressurized (6 bar). After depressurization, microbubbles cling to flocculates and climb to the top of the flotation tank (this flotation foam is clarified using a rotary filter). At laboratory scale, gluten (20 g/hL) and gelatin (10 g/hL) (each combined with bentonite and silica gel) gave turbidities of 50 and 35 NTU, respectively (6.5 and 4.1% of that of the nontreated must). The Muscat must was also clarified by static settling. The turbidity decreased by 86% for the gluten/bentonite fining and by 60% for the gelatin/bentonite fining. Visually, gluten flocculation takes longer to occur and flocculates sedimentation is longer than with gelati, but the removal of insoluble particles is more complete and leads to lower turbidities. At an industrial scale, gluten (20 g/hL) and gelatin (10 g/hL) (each combined with bentonite and silica gel) gave turbidities of 60 and 48 NTU, respectively. Turbidities measured in the tanks 14 h after the flotation showed a better efficiency for the wheat gluten (24 NTU) compared to gelatin (28 NTU). This is explained by the static settling that completed the clarifying effect of the flotation. The last experiment showed comparable efficiencies for wheat gluten and lupin proteins. BSE caused a situation of crisis (in Europe particularly) leading the public and wine-makers to lose their confidence in the use of gelatin as fining agent and to reject animal proteins in general. It is proposed here that vegetable proteins could efficiently replace gelatin.
牛海绵状脑病（BSE，疯牛病）危机致使一些酿酒商质疑明胶作为澄清剂，并拒绝使用这些动物蛋白。通过将植物蛋白（尤其是面筋蛋白）与明胶澄清处理进行比较，开始寻找明胶的替代品。克莱雷特迪耶（法国控制的法定产区）是一种起泡甜葡萄酒。酒精发酵在罐中开始，在皇冠盖瓶中继续，并在糖分完全消耗之前停止。装瓶前必须去除瓶中存在的所有颗粒，并且使葡萄汁尽可能清澈很重要。本研究涉及使用一种非常有效的浮选技术对用果胶酶处理过的麝香葡萄汁进行澄清。葡萄汁用膨润土/硅胶/蛋白质（鱼明胶、小麦面筋或羽扇豆分离蛋白）进行澄清以诱导絮凝，然后加压（6巴）。减压后，微气泡附着在絮凝物上并上升到浮选罐顶部（这种浮选泡沫用旋转过滤器进行澄清）。在实验室规模下，面筋蛋白（20克/百升）和明胶（10克/百升）（分别与膨润土和硅胶混合）产生的浊度分别为50和35 NTU（分别为未处理葡萄汁浊度的6.5%和4.1%）。麝香葡萄汁也通过静态沉降进行澄清。面筋蛋白/膨润土澄清使浊度降低了86%，明胶/膨润土澄清使浊度降低了60%。从视觉上看，面筋蛋白絮凝发生的时间更长，絮凝物沉降的时间比明胶长，但不溶性颗粒的去除更彻底，导致浊度更低。在工业规模下，面筋蛋白（20克/百升）和明胶（10克/百升）（分别与膨润土和硅胶混合）产生的浊度分别为60和48 NTU。浮选14小时后在罐中测量的浊度表明，与明胶（28 NTU）相比，小麦面筋（24 NTU）的效率更高。这可以通过完成浮选澄清效果的静态沉降来解释。最后一个实验表明小麦面筋和羽扇豆蛋白的效率相当。疯牛病引发了一场危机（特别是在欧洲），导致公众和酿酒商对使用明胶作为澄清剂失去信心，并普遍拒绝动物蛋白。在此提议植物蛋白可以有效地替代明胶。
