title: Optimization of mead production using response surface methodology.
abstract: The main aim of the present work was to optimize mead production using Response Surface Methodology. The effects of temperature (x₁: 20-30°C) and nutrients concentration (x₂: 60-120g /hL) on mead quality, concerning the final concentrations of glucose (Y₁), fructose (Y₂), ethanol (Y₃), glycerol (Y₄) and acetic acid (Y₅), were studied. Twelve operational conditions were tested. No delays and moods were observed during fermentations. The second order polynomial models determined produced satisfactory fittings of the experimental data with regard to glucose (R²=0.646, p=0.001), ethanol (R²=0.741, p=0.049), glycerol (R²=0.899, p=0.002), fructose (R²=0.902, p=0.033) and acetic acid (R²=0.913, p=0.001). The optimum extraction conditions determined in order to maximize the combined responses were 24°C and a nutrients concentration of 0.88g/L. The mead produced under these conditions had the following characteristics: ethanol concentration of 10.2%, acetic acid 0.54 g/L, glycerol 7.8 g/L, glucose 1.8 g/L and fructose 2.5 g/L. These values were in agreement with the predicted and were within the safe limit established for acetic acid and the recommended range for glycerol. Furthermore, the residual sugars concentration was also low, decreasing the possibility of occurring undesirable refermentations.
authors.affiliation: ESA-Polytechnic Institute of Bragança, Apartado 1172, Bragança, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Gomes
authors.forename: Carla
authors.initials: C
authors.lastname: Barradas
authors.forename: Teresa
authors.initials: T
authors.lastname: Dias
authors.forename: João
authors.initials: J
authors.lastname: Verdial
authors.forename: Jorge Sá
authors.initials: JS
authors.lastname: Morais
authors.forename: Elsa
authors.initials: E
authors.lastname: Ramalhosa
authors.forename: Leticia M
authors.initials: LM
authors.lastname: Estevinho
mesh_terms: D019342:Acetic Acid / Q000032:analysis / Q000378:metabolism; D000434:Alcoholic Beverages / Q000032:analysis* / Q000382:microbiology; D004040:Dietary Carbohydrates / Q000032:analysis / Q000378:metabolism; D000431:Ethanol / Q000032:analysis / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling; D063427:Food Quality; D005990:Glycerol / Q000032:analysis / Q000378:metabolism; D006722:Honey / Q000032:analysis*; D007700:Kinetics; D015233:Models, Statistical; D011174:Portugal; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D013223:Statistics as Topic; D013696:Temperature
chemical_list: D004040:Dietary Carbohydrates; D000431:Ethanol; D005990:Glycerol; D019342:Acetic Acid
keywords: Fermentation products; Mead; Optimization; Response Surface Methodology