Underutilised palm stearin as hard stock for deep-frying medium and its performance for oil uptake in instant noodles.

BACKGROUND: As a by-product of the palm oil industry, palm stearin is often overlooked despite having several beneficial properties, such as excellent stability, which is critically essential to meet the demand of the global food trend in producing safer processed food. Specifically, deep frying of food is often associated with the production of toxic compounds that could potentially migrate into the food system when oils are degraded under continuous heating. The incorporation of palm stearin is regarded as a cost-effective and efficient method to modify the fatty acid composition of oils, enhance the frying qualities and lower the degradation rate. RESULTS: This study blended 5% and 10% palm stearin into palm oil to investigate the deep-frying performance and impact on food quality. Increasing the palm stearin content improved the frying oil's oxidative and hydrolytic stability, evidenced by reduction of total polar material, free fatty acid and total oxidation value. Addition of palm stearin increased the slip melting point which improved the oil's oxidative stability but no significant increase in oil content of instant noodles was observed. Scanning electron microscopy and fluorescence microscopy showed the formation of larger pores in the noodle structure that facilitated oil retention. CONCLUSION: Blending palm stearin into frying oil enhanced the frying stability and minimally affected the oil uptake in instant noodles. This article presents the viability of blending palm stearin into frying oils to develop longer-lasting frying oils. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Palm-based cellulose nanofiber isolated from mechano-chemical processing as sustainable rheological modifier in reduced fat mayonnaise.

Reducing fat intake from our daily diet serves to be an effective way to combat the rising obesity issue worldwide. Hence, reducing fat content in mayonnaise, a high fat food product, is one of the primary trends in the food industry. To date, research on the use of nanocellulose, a new and emerging form of fat mimetic, in mayonnaise formulation remains limited. This study sets out to formulate reduced fat 5%, 15%, and 30% mayonnaise using varying concentration of nanocellulose synthesized from palm pressed fiber followed by a 20-day stability study. Nanocellulose was synthesized with particle size of 106.0 ± 18.7 nm and zeta potential of -72.5 ± 2.26 mV. It was used as fat mimetic in mayonnaise. Rheological analysis conducted showed that incorporation of nanocellulose into reduced fat mayonnaise formulation was able to counteract the loss of viscosity in mayonnaise caused by fat content reduction. This finding was further supported by the smaller oil droplets that are closely packed in reduced fat mayonnaise formulation when viewed under light microscope. Nonetheless, significant oil droplet coalescence was found in reduced fat mayonnaise formulations during storage period which could lead to loss of viscosity. Taken together, these findings suggest that CNF was able to act as fat mimetic upon formulation of mayonnaise but the same cannot be said during long term storage of mayonnaise. PRACTICAL APPLICATION: We successfully isolated nanocellulose from palm biomass (palm pressed fiber) using green approach and used it as a fat replacer for preparation of 5%, 15%, and 30% reduced fat mayonnaise. A computation study revealed a strong binding affinity of the nanocellulose on the lipase active site essential to inhibit the digestion of fats and oils. Therefore, nanocellulose demonstrated a huge potential to be used as not only as fat replacer but also rheological modifier for the development of reduced fat or vegan foods.