Quality retained with trans free bakery shortening, says study
Findings from research undertaken by scientists based at the University of Delhi was published in the International Journal of Food Science and Technology and indicates that using IE shortenings in place of hydrogenated fats led to a significant decrease in trans fatty acids (TFA).
Often alternatives to hydrogenated fat, in order to provide products that deliver the desired performance in terms of functionality and stability, can cause a substantial increase in the saturated fatty acid (SFA) content of baked goods and other products.
However, the authors note that their project shows that using IE shortening resulted in only a marginal increase in SFA content of the short dough biscuits produced.
Artificial trans fats in the form of partially hydrogenated vegetable oils have been widely used by food manufacturers for a century, but evidence has mounted over the past decade linking the fats with increased risk of heart disease.
They have been shown to increase levels of low-density lipoproteins (LDL, or ‘bad’ cholesterol) and simultaneously lower levels of high-density lipoproteins (HDL, or ‘good’ cholesterol).
The researchers explained that the interesterification process involves the rearrangement of the FA on the glycerol backbone of the fat in the presence of a chemical catalyst or an enzyme.
This technique, continued the research team, modifies the melting and crystallisation behaviour of the fat, thus producing fats with the desirable physical properties but without TFA.
Previous studies have shown that IE was successfully applied in cake shortening production, resulting in a decrease in TFA levels, and the objective of this study was to determine the suitability of IETFS in the production of short dough biscuits, they added.
Short dough biscuits were prepared using the Lawson formulae and two sets of biscuits were produced with the different shortenings, a control which consisted of HS and the other using IETFS in batches of 166 biscuits, said the authors.
They said that bakery shortening and sugar were creamed for five minutes together with lecithin, BHT and flavour using an electric hand mixer at medium speed, and then refined wheat flour, sodium chloride, sodium bicarbonate, ammonium bicarbonate mixture was incorporated.
A standardised amount of water was added, continued the researchers, and the dough was kneaded for seven minutes, and then divided into smaller portions and filled into the biscuit maker.
They said the biscuits were moulded on to the greased baking tray, baked at 180°C for 25 minutes and cooled for 1 hour at ambient temperature before being packed in 100 g metallised pouches and stored until needed for further analysis.
The physical properties of the baked biscuits measured were height, diameter and hardness, while a sensory panel assessed the products for colour, texture, flavour, appearance and overall acceptability, added the authors.
The researchers said that the results of the sensory analysis revealed that biscuits made with HS were rated lower than trans free biscuits by the panellists on all the attributes, with the findings also demonstrating that the IE shortening had 0.3 per cent trans fat comprising of eliadic and linoeliadic fractions as opposed to HS which had 14 per cent trans fat.
Higher diameter was observed with IETFS as compared to HS. And after eight months of storage, both biscuit types had similar moisture content but the IETFS products had significantly lower hardness by the end of the storage period, said the team.
They explained that biscuits made with HS had higher height owing to their lower shortening effect, which resulted in greater gluten development, while the melting point of hydrogenated fat was found to be 40.2°C and that of IETFS was 38.8°C.
“This could be attributed to higher trans fat content of HS as opposed to 0.3 per cent trans fat in IETFS,” continued the authors.
They added that higher diameter and lesser height resulted in higher spread ratio of biscuits made with IETFS indicating better overall quality.
The team found that the fatty acid fraction of the control biscuits was: saturated fat, 51.6 per cent, trans fat, 14.5 per cent, monounsaturated fat, 28 per cent and polyunsaturated fat, 5.9 per cent, while for the IETFS biscuits it was: saturated fat, 54.8 per cent, trans fat, 0.6 per cent; monounsaturated fat, 38.1 per cent; and polyunsaturated fat, 6.5 per cent.
“The trans fat free biscuits contain negligible amount (0.1 g 100 g of biscuits) of trans fat and as per FDA, in foods containing less than 0.5 g trans fat per serving, the content of trans fat, when declared, shall be expressed as zero,” claim the researchers.
And they concluded that the trans free IE shortening can be used effectively to provide desirable characteristics for baked products such as biscuits.
Source: International Journal of Food Science and Technology
Published online ahead of print
Title: Performance and fatty acid profiling of interesterified trans free bakery shortening in short dough biscuits
Authors: C. Handa, S. Goomer, A. Siddhu