Using hydrocolloids to decrease oil absorption in banana chips

Abstract

The aim of this research was to investigate the influence of hydrocolloids (alginate, CMC and pectin) on the oil absorption in fried banana chips. The control banana chips (no hydrocolloid treatment) had oil content as high as 40 g/100 g sample, whereas the sample blanched in 0.5 g CaCl₂/100 ml water and following with immersion in 1 g alginate/100 ml water exhibited a small decrease of oil uptake (p ≤ 0.05) to 38 g/100 g sample. The others which treated with 0.5 g CaCl₂/100 ml and 1 g pectin/100 ml water, and with 0.25 g CaCl₂/100 ml water and 1 g CMC/100 ml water absorbed much less oil (p ≤ 0.05), approximately 23 g/100 g sample. Besides, pectin-treated chips had higher sensory scores in all attributed than CMC-treated sample. These resulted showed that pectin was the most effective hydrocolloid for low fat fried banana chip production. Scanning electron microscope photographs indicted that coating banana chips with pectin was effective in protecting the cellular structure of the banana tissue from damage during deep-fat frying.

Introduction

Frying is one of the oldest cooking processes of food, inducing chemical and physical properties changes including starch gelatinization, protein denature, water vaporization and crust formation (Mallikarjunan et al., 1997, Rimac-Brncic et al., 2004). This process affects heat and mass transfer, causing oil movement into the product as well as water movement from the product into the oil.

Deep-fat frying is a widely used method for preparing foods. The aim of deep-fat frying is to seal the food surface by immersing food pieces in the hot oil so that all flavors and juices are retained inside. The high temperature causes partial evaporation of water, which moves away from the food and through the surrounding oil (Khalil, 1999, Moyano et al., 2002). The soft and moist interior along with the porous crispy crust provides increased palatability to foods (Akdeniz et al., 2006, Mallikarjunan et al., 1997, Mellema, 2003). Moreover, interest in low fat products has recently increased. Fried foods also contain high amount of fat, yet remain popular. Interest in low fat product has recently increased as excess fat consumption is considered to heighten blood cholesterol, high blood pressure and coronary heart disease. Thus, research in reducing oil absorption during deep-fat frying has been intense in recent years. Hydrocolloids have been used as multifunctional additives in food processing to improve functional properties such as viscosity, water binding capacity and emulsion stability (Aguilera and Gloria-Hernández, 2000, Bravin et al., 2006, Phillips and Williams, 2000, Whistler and BeMiller, 1993).

Hydrocolloids are of special interest because they possess good barrier property against oxygen, carbon dioxide and lipids which could reduce oil absorption during deep-fat frying (Albert and Mittal, 2002, Mallikarjunan et al., 1997, Rimac-Brncic et al., 2004, Williams and Mittal, 1999). Some of the most useful hydrocolloids are cellulose derivatives such as methyl cellulose (MC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) and carboxyl methyl cellulose (CMC). All these cellulose derivatives are water soluble with good film-forming properties (Priya, Singhal, & Kulkarni, 1996). Alginate and pectin are widely used in food systems to stabilize and to modify the rheology of food. The most useful property is gelation, which is formed by intermolecular association with polyvalent cations (Albert and Mittal, 2002, Khalil, 1999, Rimac-Brncic et al., 2004).

Banana chips are one of many popular One Tambon One Product (OTOP) snack in Ubon Ratchathani, Thailand. However, published data of fried banana chips is very limited. The main objective of this study was to investigate the influence of hydrocolloids (alginate, carboxyl methyl cellulose and pectin) on the oil absorption in banana chips.