Formation of acrylamide in biscuits during baking under different heat transfer conditions

Influence of baking conditions and formulation on furanic derivatives, 3-methylbutanal and hexanal and other quality characteristics of lab-made and commercial biscuits

Biscuit baking can cause the formation of heat-related toxic compounds, mainly through the Maillard reaction, including some volatile organic compounds (VOCs) that are potentially carcinogenic to humans. This study investigates the effects of different baking conditions and recipes on quality characteristics (moisture, water activity, colour, texture) and on the concentration of some VOCs (furfural, furfuryl acetate, 5-methylfurfural, furfuryl alcohol, 3-methylbutanal, hexanal) in biscuits. Specifically, lab-made biscuits baked under static and ventilated conditions and three commercial biscuit types categorised as shortbreads with eggs, with chocolate chips and dry petits were evaluated. Concerning the lab-made biscuits, the ventilated mode resulted in faster baking and a slightly lower concentration of investigated VOCs compared to the static mode. Besides the process conditions, the recipe also played a role in the final quality and target volatiles, whose concentrations were lower in dry petits than in shortbreads, which are characterised by higher sugar and fat contents.

Formulation and Processing Strategies to Reduce Acrylamide in Thermally Processed Cereal-Based Foods

Acrylamide, a thermal process contaminant, is generated in carbohydrate-rich foods processed at high temperatures (above 120 °C). Since acrylamide indicates a human health concern, the acrylamide contents of various foods and the dietary exposure of the population to acrylamide are very well investigated. Commonly consumed foods in the daily diet of individuals such as bakery products, potato products and coffee are major dietary sources of acrylamide. In recent years, dietary exposure levels of the population and mitigation measures for reducing acrylamide in different food products have gained importance to decrease the public's exposure to acrylamide. Since the complete elimination of acrylamide in foods is not possible, various mitigation measures to reduce acrylamide to levels as low as reasonably achievable have been developed and applied in the food industry. Mitigation strategies should be applied according to the different product categories during agricultural production, formulation, processing and final consumer preparation stages. The aim of this review is to evaluate formulation and processing strategies to reduce acrylamide in various cereal-based food products and to discuss the applicability of mitigation measures in the food industry by taking into consideration the organoleptic properties, nutritional value, cost and regulations in the light of current knowledge.

Reducing Dietary Acrylamide Exposure from Wheat Products through Crop Management and Imaging

The nutritional safety of wheat-based food products is compromised by the presence of the processing contaminant acrylamide. Reduction of the key acrylamide precursor, free (soluble, non-protein) asparagine, in wheat grain can be achieved through crop management strategies, but such strategies have not been fully developed. We ran two field trials with 12 soft (biscuit) wheat varieties and different nitrogen, sulfur, potassium, and phosphorus fertilizer combinations. Our results indicated that a nitrogen-to-sulfur ratio of 10:1 kg/ha was sufficient to prevent large increases in free asparagine, whereas withholding potassium or phosphorus alone did not cause increases in free asparagine when sulfur was applied. Multispectral measurements of plants in the field were able to predict the free asparagine content of grain with an accuracy of 71%, while a combination of multispectral, fluorescence, and morphological measurements of seeds could distinguish high free asparagine grain from low free asparagine grain with an accuracy of 86%. The acrylamide content of biscuits correlated strongly with free asparagine content and with color measurements, indicating that agronomic strategies to decrease free asparagine would be effective and that quality control checks based on product color could eliminate high acrylamide biscuit products.

Influence of baking and frying conditions on acrylamide formation in various prepared bakery, snack, and fried products

The core objective of the present study was to evaluate the influence of baking/frying times and temperatures on the formation of acrylamide in bakery, snack, and fried products such as biscuits, muffins, pizza, cakes, samosa, paratha rolls, nuggets, and potato cutlets during baking/frying at different times and temperature conditions. First of all, the raw material, especially flour, was tested for its proximate composition and rheological characteristics. The quantification of acrylamide produced during the processing of different products was carried out through the HPLC method. A sensory evaluation of these food samples was also carried out to find out the acceptability differences. The raw material was found to have good rheological properties and proximate composition. The results revealed that different times and temperature regimes influenced the formation of acrylamide in those products. Among the bakery products, the highest concentrations of acrylamide were observed in biscuits (126.52 μg/kg) followed by muffins (84.24 μg/kg), cake (71.21 μg/kg), and pizza (62.42 μg/kg). The higher contents of acrylamide were found in paratha roll (165.92 μg/kg) compared to samosa (100.43 μg/kg), whereas among snacks, potato cutlets (135.71 μg/kg) showed higher concentrations than nuggets (43.04 μg/kg). It was observed that baking or frying all the investigated products at higher temperatures produced slightly more acrylamide concentrations. The prepared products in the present study were also accepted sensorially by the panel of judges. So, it was concluded that baking or frying at higher temperatures resulted in higher concentrations of acrylamide compounds in different products in the present study.

Antioxidants of Amaranth, Quinoa and Buckwheat Wholemeals and Heat-Damage Development in Pseudocereal-Enriched Einkorn Water Biscuits

A viable approach to improve the nutritional quality of cereal-based foods is their enrichment with pseudocereals. The aim of this research was to evaluate the antioxidant properties of amaranth, quinoa and buckwheat, and the heat damage of water biscuits (WB) produced from either wholemeal or refined flour of einkorn and enriched with 50% buckwheat, amaranth or quinoa wholemeal. Buckwheat had the highest tocols content (86.2 mg/kg), and einkorn the most carotenoids (5.6 mg/kg). Conjugated phenolics concentration was highest in buckwheat (230.2 mg/kg) and quinoa (218.6 mg/kg), while bound phenolics content was greatest in einkorn (712.5 mg/kg) and bread wheat (675.7 mg/kg). The all-wholemeal WB had greater heat damage than those containing refined flour (furosine: 251.5 vs. 235.8 mg/100 g protein; glucosylisomaltol: 1.0 vs. 0.6 mg/kg DM; hydroxymethylfurfural: 4.3 vs. 2.8 mg/kg DM; furfural: 8.6 vs. 4.8 mg/kg DM). The 100% bread wheat and einkorn wholemeal WB showed greater heat damage than the WB with pseudocereals (furfural, 9.2 vs. 5.1 mg/kg; glucosylisomaltol 1.1 vs. 0.7 mg/kg). Despite a superior lysine loss, the amino-acid profile of the pseudocereals-enriched WB remained more balanced compared to that of the wheats WB.

Mitigation of Acrylamide Content in Biscuits through Combined Physical and Chemical Strategies

Acrylamide in biscuits represents a major concern. This research work was aimed at modifying the current formulation of biscuits to reduce the acrylamide content while maintaining the chemical, physical, and sensory characteristics of the original product. A strategy based on the FoodDrinkEurope Acrylamide Toolbox was adopted. The content of the leavening agent ammonium bicarbonate, the baking temperature program, and the time duration of steam released during the baking process were the three factors evaluated through a factorial design of experiment. The partial replacement of ammonium bicarbonate (from 9.0 g to 1.5 g per 500 g of flour) with sodium bicarbonate (from 4.5 g to 12.48 g), lowering of the temperature in the central phase of the baking process (from 170 °C to 150 °C), and the release of steam for 3 min resulted in an 87.2% reduction in acrylamide concentration compared to biscuits of reference. CIELab color indices and a_w were the parameters that showed the most significant correlation with acrylamide concentration in biscuits and could, therefore, become markers to predict the acrylamide content along production lines for an instant evaluation.

Effect of Partial Substitution of Flour with Mealworm (Tenebrio molitor L.) Powder on Dough and Biscuit Properties

Mealworm (Tenebrio molitor L.) is a type of edible insect rich in protein that has become popular as a protein-alternative ingredient in flour-based products to improve the nutritional properties of baking products. The mealworm powder substitution affected the pasting, farinograph, extensograph properties of wheat flour and the texture, nutritional, and sensory properties of the resulting soda biscuit. The pasting parameters (peak viscosity, trough viscosity, breakdown viscosity, final viscosity, and setback viscosity) and the water absorption decreased with the increased mealworm powder substitution level, which was ascribed to the dilution effect of mealworm powder. The farinograph parameters remained similar up to 15% substitution level. The extensograph results showed that mealworm powder substitution decreased the elastic properties of wheat dough as indicated by the consistently decreased extensibility, stretching energy, and stretching resistance, resulting in a significantly decreased baking expansion ratio of the soda biscuit. The protein, lipid, and dietary fiber content of the biscuits increased accordingly with the increased mealworm powder substitution level. The protein content of the soda biscuit was gradually increased from 9.13/100 g for the control (M0) to 16.0/100 g for that supplemented with 20% mealworm powder (M20), accompanied with the significantly increased essential amino acid content. Meanwhile, the fat and dietary fiber content of M20 exhibited 20.5 and 21.7% increase compared to those of M0. The score of the sensory attributes showed no significant difference up to 15% substitution level. The results demonstrated the 15% mealworm powder substitution level would not significantly affect the farinograph property, microstructure of wheat dough, and sensory acceptability.