UTJECAJ EKSTRAKTA KESTENA (FARMATAN®) NA KINETIKU IN VITRO FERMENTACIJE CELULOZE

Four different concentrations [0 (control), 0.33, 0.67 and 1.33 mg/ml medium)] of sweet chestnut extract (Farmatan®, Tanin, Slovenia) were used to investigate their effect on the kinetics of in vitro fermentation of pure cellulose (BWW 40, J. Rettenmaier & Söhne, Germany). Gas produced was measured at 0, 2, 4, 6, 8, 10, 12, 24, 36, 48, 72 and 96 h after the start of incubation. Gompertz model was used to estimate kinetic parameters “B” (total potential gas production), “C” (relative degradation rate) and “A” (constant decay in relative degradation rate). First and second derivative of Gompertz model were used to calculate the maximum fermentation rate (MFR) and time of maximum fermentation rates (TMFR), respectively. Comparing with the control (550.8 ml/g DM) the total potential gas production significantly decreased (p < 0.05) when 0.33 and 0.67 mg of Farmatan® were added to the medium (474.0 ml/DM and 504.2 ml/g DM, respectively). On contrary, the highest concentration of Farmatan® (1.33mg/ml medium) did not decrease the total potential gas production. Maximum fermentation rate of cellulose (21.4 ml/h) occurred after 13 h of incubation. Increasing concentrations of Farmatan® decreased MFR (p < 0.05) from 21.4 ml/h (control) to 16.6 ml/h (0.33 mg/ml medium), 18.4ml/h (0.67 mg/ml medium) and 10.5 ml/h (1.33 mg/ml medium). Farmatan® significantly increased (p < 0.05) TMFR. The increase was the greatest when 0.67 mg of Farmatan® was added to the medium (29.2 h). Lag phase of cellulose (4.4 h in control) did not change significantly (p < 0.05) with increasing concentrations of Farmatan®.Četiri različite koncentracije [0 (kontrola), 0.33, 0.67 i 1.33 mg/ml medija)] ekstrakta slatkog kestena (Farmatan®, Tanin, Slovenija) korištene su za istraživanje učinka na kinetiku in vitro fermentaciju čiste celuloze (BWW 40, Rettenmaier i Söhne, Germany). Proizvodnja plina mjerena je 0, 2, 4, 6, 8, 10, 12, 24, 36, 48, 72 i 96 sati nakon početka inkubacije. Model „Gomperz“ je korišten kako bi se utvrdili parametri kinetike „B“ (ukupna potencijalna proizvodnja plina), „C“ (relativno vrijeme razgradnje) i „A“ (konstantno nestajanje u relativnom vremenu razgradnje). Prva i druga derivacija „Gomperz“ modela je korištena kako bi se izračunala maksimalna brzina fermentacije (MBF) i vrijeme maksimalnih brzina fermentacije (VMBF). U usporedbi s kontrolom (550.8 ml/g ST), ukupna potencijalna proizvodnja plina značajno se smanjila (p < 0.05) kada je dodano 0.33 i 0.67 mg Farmatana® u medij (473.0 ml/ST i 504.2 ml/ST, za svako posebno). Nasuprot tome, najviša razina Farmatana® (1.33 mg/ml medija) nije smanjila ukupnu potencijalnu proizvodnju plina. Maksimalna brzina fermentacije celuloze (21.4 ml/h) nastupila je 13 sati nakon inkubacije. Povećanje koncentracije Farmatana® smanjilo je MFR (p < 0.05) od 21.4 ml/h (kontrola) na 16.6 ml/h (0.33 mg/ml medija), 18.4 ml/h (0.67 mg/ml medija) i 10.5 ml/h (1.33 mg/ml medija). Farmatan® je značajno povećao (p < 0.05) TMFR. Povećanje je bilo najviše kada je u medij dodano 0.67 mg Farmatana® (29.2 h). Lag faza celuloze (4.4 h u kontroli) nije se značajno (p < 0.05) promijenila s povećanjem koncentracije Farmatana®