INVESTIGATION OF THE EFFECT OF APPLE POMACE ON THE TEXTURAL CHARACTERISTICS, FIBRE CONTENT, AND MOISTURE CONTENT OF SPONGE CAKES

Abstract

Apple pomace, a by-product from apple processing industries, is a popular raw material, which has characteristics of a rich nutritional component, so its utilisation is of great interest. The purpose of this research was to study the effect of apple pomace on the textural characteristics and moisture and fibre contents of sponge cakes. Besides, the relationship between the properties under examination has been investigated. Rheology encompasses many characteristics of the product and plays a pivotal role in consumer acceptance. Rheology, in particular, considers the flow and deformation of bakery products. Sponge cakes were produced with wheat flour partially (by 15%, 25%, and 50%) replaced with apple pomace powder. The addition of 15% and 25% of apple pomace to sponge cakes leads to significant differences in the textural indicators, and with the addition of 50% of apple pomace, there is a maximum improvement in all textural characteristics. With an increase in the amount of apple pomace added, there is an increase in the content of fibre and moisture in the sponge cakes. Apple pomace is used as a valuable source of food fibre in the cake technology. The correlation analysis has found that fibre and moisture changes exhibit a strong correlation with rupture deformation and stickiness. Very strong and statistically significant dependence with a negative value has only been found between the moisture content and stickiness (r = ‑0.965, p<0.05). This statistically significant dependence shows that as the fibre content in sponge cakes increases, the stickiness values decrease due to the negative value of the Pearson coefficient (r = -0.965, p<0.05). From the correlation coefficients, it has been shown that the rupture force and deformation exhibit the same very strong and statistically significant correlation with the textural characteristics – rupture energy, hardness, gumminess, and compressive strength (r = 0.993, r = 0.984, r = 0.996, and r = 0.999, p<0.05). The Pearson correlation coefficients of rupture energy are positive and statistically significant in relation to hardness, gumminess, and compressive strength (r = 0.957, r = 0.983, and r = 0.992, p<0.05). These strong and statistically significant dependences are found between Pearson’s hardness coefficient on the one hand and gumminess and compressive strength on the other (r = 0.992 and r = 0.984, p<0.05).