Optimizacija infeed formule za kapsuliranje ekstrakta iz iskorišćene mlevene kafe upotrebom response surface methodology

Wiraya Khotchapong,Niramol Punbusayakul

doi:10.5937/jpea1903108k

Abstract

The purpose of this paper is to optimize the ratio of wall materials (chitosan (CH): maltodextrin (MD), X1) and spent coffee ground extract (SCGE) to the complex wall material (X2), i.e. the so-called infeed formula for the SCGE encapsulation by freeze drying. The response surface methodology (RSM), based on the central composite design (CCD), was applied to obtain the infeed formula, providing the best encapsulated SCGE properties (encapsulation yield (EY), hygroscopicity (HG), water solubility index (WSI), total phenolic compounds (TPC) and encapsulation efficiency (EE)). Multiple regression analysis was performed to derive a second-order polynomial equation for predicting properties. The EY (R2 = 0.80), HG (R2 = 0.95), WSI (R2 = 0.96) and TPC (R2 = 0.97) fitted the data well, and was ultimately used to plot a response surface. The plots obtained indicate that the EY and WSI significantly increased during the experimental process, whereas the HG and TPC decreased with the decreasing X1 and X2 (p≤ 0.05). The equations were used to optimize the infeed formula. The results obtained show that the infeed formula with the CH-to-MD of 30:70 and the SCGE-to-the-wall material of 90:10 would provide the most favorable outcomes (EY (80 %), HG (17g/100 g SCGE db), WSI (88 %) and TPC (5.27 g gallic acid equivalent/100 g SCGE db)).

Highlights

Spent coffee ground (SCG) is a by-product of the coffee brewing process, yielding approximately 1.86 kg of SCG per a kilogram of the coffee ground produced (Murthy and Naidu, 2012)
The most common wall materials used in the food industry include carbohydrates, proteins and lipids (Fang and Bhandari, 2010)
The purpose of this paper is to optimize the ratio of wall materials (CH-MD) and SCGE to the complex wall material for encapsulation of SCGE by freeze drying using the response surface methodology (RSM) in order to maximize the bioactive compounds in the encapsulated SCGE

Summary

Introduction

Spent coffee ground (SCG) is a by-product of the coffee brewing process, yielding approximately 1.86 kg of SCG per a kilogram of the coffee ground produced (Murthy and Naidu, 2012). Various authors have reported that SCG is a rich source of bioactive compounds (Klangpetch, 2017; Ramalakshmi et al, 2009). Those compounds include caffeine, trigonelline and chlorognic acid, etc. Encapsulation has been reported to facilitate the protection of bioactive compounds in raw materials from degradation during processing and storage, while concealing unpleasant flavor and taste (Nedovic et al, 2011). The most common wall materials used in the food industry include carbohydrates (starch, maltodextrins, chitosan, dextran, cyclodextrins), proteins (gluten, casein, gelatin, albumin, whey protein, soy protein) and lipids (wax, paraffin, oils, fats) (Fang and Bhandari, 2010).

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Results