Coffee silverskin as fat replacer in cake formulations and its effect on physical, chemical and sensory attributes of cakes

Highlights

• Water treated coffee silverskin can be used as a fat replacer in cakes.

• Water treatment of coffee silverskin had positive effects on cake characteristics.

• Coffee silverskin is a good alternative for the enrichment of cakes with fiber.

Abstract

Coffee silverskin untreated and treated with water has been studied as a potential fat substitute in cake and the effects of the replacement of 20, 25 and 30% of fat by coffee silverskin on physical, chemical and sensory attributes of cakes were evaluated. Replacement of fat by coffee silverskin did not significantly alter the specific volume and weight loss of the cakes. L* and b* values of crumb decreased, whereas a* value increased, hardness and chewiness of the cakes increased, whereas springiness and cohesiveness decreased. Ash and antioxidant activity of cakes increased with coffee silverskin and water treated coffee silverskin enhanced the moisture content of cakes. Sensory quality of cakes with water treated coffee silverskin showed similarity with control cake in terms of crumb porosity, cohesiveness, moistness, oiliness and sweetness. As the substitution level of water treated coffee silverskin increased perceived oiliness of cakes did not change. Coffee and bitter taste intensity was not found to be strong in cakes with water treated coffee silverskin. Water treated coffee silverskin could be used as fat substitute up to 30% in cake formulations to improve cake for high fiber content, with no significant alterations on cake characteristics.

Introduction

During the past ten years, consumers show an interest in ready to eat foods, low calorie and healthy foods (Ayadi, Abdelmaksoud, Ennouri, & Attia, 2009). However, changing the amount of ingredients to reduce the calorie content of the food may affect texture, mouthfeel, flavor and appearance of product negatively. On the other hand, as the consumers become aware of the need to increase fiber in their diet, the demand for healthful, flavorful, rich in fiber food increases (Singh, Liu, & Vaughn, 2012). A promising way for the food industry to produce healthy food without losing taste of eating can be to replace fat with dietary fiber (Kim et al., 2012).

Coffee silverskin is a tegument of the outer layer of coffee bean which is a by-product of the roasting process. It has high dietary fiber content and antioxidant capacity due to the concentration of phenolic compounds (Murthy & Naidu, 2012). Moreover, it attracts attention with high protein and ash, low fat and reducing carbohydrate contents (Borrelli, Esposito, Napolitano, Ritieni, & Fogliano, 2004). However, the presence of organic material such as cellulose, hemicellulose, proteins, fat, polyphenols, minerals and melanoidins by the Maillard reaction during the roasting process makes coffee silverskin highly pollutant due to requirement of a high amount of oxygen for its disintegration. For this reason, the coffee silverskin has a risk of polluting the environment if thrown into the environment. Despite all these negative features, it has been shown that in some of the studies carried out the coffee silverskin can be used in useful applications due to its nutritional and functional properties (Jiménez-Zamora, Pastoriza, & Rufián-Henares, 2015). Murthy and Naidu (2012) noted that the coffee silverskin can be used in breakfast cereals, bread, biscuits and snacks.

There are few studies which used fiber as fat replacer in bakery products. Martínez-Cervera, Salvador, Muguerza, Moulay, and Fiszman (2011) replaced fat by cocoa fiber in chocolate muffins and investigated the effect of cocoa fiber on chocolate muffins. In another study chia mucilage gel was used to reduce fat in pound cake (Felisberto et al., 2015). Apart from these peach in muffin (Grigelmo-Miguel, Carreras-Boladeras, & Martín-Belloso, 2001), apple pomace (Min, Bae, Lee, Yoo, & Lee, 2010) and apricot kernel flour (Seker, Ozboy-Ozbas, Gokbulut, Ozturk, & Koksel, 2010) in cookies, chia in sweet pan bread (Zettel & Hitzmann, 2016) was used as fat replacer. But to the best of our knowledge no study has been carried out regarding coffee silverskin used as fat replacer in cake.

In this study it was aimed to determine the influence of coffee silverskin as fat substitution in cake formulation. For this purpose, cakes were formulated with 0%, 20%, 25% and 30% replacement of fat with coffee silverskin and the effect of the replacement of vegetable fat by coffee silverskin on appearance, color, texture and sensory quality of cakes was determined.