Potato (Solanum tuberosum L.) nutritional changes associated with French fry processing: Comparison of low-temperature long-time and high-temperature short-time blanching and frying treatments

The effect of cold atmospheric plasma pretreatment on oil absorption, acrylamide content and sensory characteristics of deep-fried potato strips

This study investigated the impact of 60 kV Cold Atmospheric Plasma (CAP) pretreatment for varying durations (5, 10, and 15 min) on potato strip characteristics before and after frying, emphasizing oil uptake, acrylamide formation. Potato samples treated with cap showed significantly better physicochemical characteristics. Scanning electron microscopy revealed deformation of cell wall due to CAP treatment. Fourier-transform infrared spectroscopy indicated structural changes, while X-ray diffraction analysis suggested that starch remained amorphous state in CAP-pretreated samples. Post-frying, CAP-treated potato strips exhibited altered oil distribution with reduced absorption, possibly due to microstructural changes. CAP substantially reduced acrylamide formation during frying by degrading asparagine and inactivating amylase. CAP affected strip color, with increased brightness and decreased redness and yellowness after 14 days. Sensory evaluation showed no significant difference, with prolonged CAP-treated strips receiving higher overall acceptability scores. These findings highlight CAP as a non-thermal technology to enhance fried potato product quality and safety.

Biochemical characterization of glutaminase-free L-asparaginases from Himalayan Pseudomonas and Rahnella spp. for acrylamide mitigation

L-asparaginase having low glutaminase activity is important in clinical and food applications. Herein, glutaminase-free L-asparaginase (type I) coding genes from Pseudomonas sp. PCH182 (Ps-ASNase I) and Rahnella sp. PCH162 (Rs-ASNase I) was amplified using gene-specific primers, cloned into a pET-47b(+) vector, and plasmids were transformed into Escherichia coli (E. coli). Further, affinity chromatography purified recombinant proteins to homogeneity with monomer sizes of ~37.0 kDa. Purified Ps-ASNase I and Rs-ASNase I were active at wide pHs and temperatures with optimum activity at 50 °C (492 ± 5 U/mg) and 37 °C (308 ± 4 U/mg), respectively. Kinetic constant Km and Vmax for L-asparagine (Asn) were 2.7 ± 0.06 mM and 526.31 ± 4.0 U/mg for Ps-ASNase I, and 4.43 ± 1.06 mM and 434.78 ± 4.0 U/mg for Rs-ASNase I. Circular dichroism study revealed 29.3 % and 24.12 % α-helix structures in Ps-ASNase I and Rs-ASNase I, respectively. Upon their evaluation to mitigate acrylamide formation, 43 % and 34 % acrylamide (AA) reduction were achieved after pre-treatment of raw potato slices, consistent with 65 % and 59 % Asn reduction for Ps-ASNase I and Rs-ASNase I, respectively. Current findings suggested the potential of less explored intracellular L-asparaginase in AA mitigation for food safety.

Comparative study of conventional frying and air frying on the quality of potatoes (Solanum tuberosum L.)

The human being has historically consumed fried foods for centuries; however, conventional frying has a disadvantage, immersion in vegetable and/or animal oils, which leads to the search for different options. This is why air frying is a good alternative, which still has a wide field of study. In this work, frozen French fries of a brand marketed in Mexico that were subjected to frying in canola oil and air frying were compared. They were evaluated through the change in the removed moisture content, water activity, color profile, hardness, fracturability, and surface damage by SEM, thermal analysis by MDSC, and chemical by FTIR-ATR spectroscopy. Air-fried French fries were found to contain about 48% less moisture, fewer perceptible color changes, and less surface damage translated into better crunchiness compared with conventionally fried. It was also found that the changes at the chemical level are smaller, mainly attributed to the absence of canola oil and that the thermal transitions are more stable in terms of temperatures and enthalpies, which makes it possible to emphasize that air frying is a good alternative for developing new fried products that allow expanding the variety of these in the market without sacrificing some quality attributes.

Effect of Preliminary Treatment by Pulsed Electric Fields and Blanching on the Quality of Fried Sweet Potato Chips

The effects of pulsed electric fields (PEF) and blanching pretreatments on frying kinetics, oil content, color, texture, acrylamide (AA) content, and microstructure have been investigated in this paper. The total PEF pretreatment duration was t_PEF = 0.2 s with an intensity of E = 1 kV/cm; blanching was studied at 85 °C for 5 min. The results demonstrated that pretreatment significantly reduced the moisture ratio and oil content by 25% and 40.33%, respectively. The total color change ΔE value of the pretreated samples was lower than that of the untreated samples. In addition, pretreatment increased the hardness of the sample after frying, and the AA content in the fried samples pretreated with PEF + blanching was reduced by approximately 46.10% (638 μg/kg). Finally, fried sweet potato chips obtained by the combined pretreatment exhibited a smoother and flatter cross-sectional microstructure.

Similarities and differences in the nutritional composition of nuts and seeds in Serbia

Nuts and seeds are an indispensable part of the plant-based diet, which is becoming increasingly popular due to the evidence of their health benefits and contribution to sustainability and planetary health. Since the health effects of consuming nuts and seeds directly depend on their nutritional composition and consumed amount, it is essential to know the exact chemical composition of each nut and seed so that appropriate dietary interventions can be adequately planned. The present study aimed to examine the chemical composition of nuts and seeds obtained from the Serbian market and to highlight the similarities and differences in their nutritional composition. In twenty-four samples of nuts and seeds, the content of total lipids, including fatty acid profile, total proteins, including amino acid profile, total carbohydrates (sugars and fibers), phytosterols, and minerals were determined. Content of selected nutrients in grams (g) or milligrams (mg) of nuts and seeds was expressed in one portion (28 g) and as a percentage of contribution of Reference Intakes (% RI) and Dietary Reference Value (% DRV) for macronutrients and minerals, respectively. Some of the seed representatives appeared to be rich sources of essential omega-3 fatty acid, α-linolenic acid (ALA) (flax seed vs. walnut, 6.50 vs. 0.56 g per portion, respectively), dietary fibers (chia seed vs. raw almond, 10.6 vs. 3.4 g per portion, respectively), calcium (black sesame seed vs. almond roasted, 32.4% NRV vs. 8.1% NRV per portion, respectively), magnesium (hemp seed vs. Brazil nut, 38.3% NRV vs. 27.8% NRV per portion, respectively), and zinc (hemp seed vs. pine nut, 21.4% NRV vs. 17.6% NRV per portion, respectively). Our results highlighted the crucial role of seeds in the diet, especially as a better source of nutrients compared to nuts. Furthermore, it was seen that nuts and seeds are different and complementary in their composition. Thus, in order to meet the needs for certain nutrients for which nuts and seeds are used as dietary sources (essential fatty acids, minerals, dietary fibers), it would be beneficial to combine both nuts and seeds as a part of a healthy dietary pattern.

Influence of Water, NaCl and Citric Acid Soaking Pre-Treatments on Acrylamide Content in French Fries Prepared in Domestic Conditions

The aim of this study was to investigate the influence of some pre-treatment applications toward acrylamide mitigation in potatoes fried in domestic conditions modeled after those found in Romania, by using a pan and a fryer. Before being fried in a pan, potato strips were treated in one of the following ways: soaked in cold water for 15, 60, and 120 min (a); soaked in hot water at different combinations of temperatures and durations (60, 70, 80 °C for 5, 10, 15 min) (b); soaked in a NaCl solution (c), and; in a citric acid solution (d) both solutions of 0.05% and 1% concentration for 30 min. For potatoes fried in a fryer, the (a) pre-treatment and soaking in water at 80 °C for 5, 10, and 15 min were applied. Untreated samples were used as a control. French fries were analyzed in terms of moisture and acrylamide content, color, and texture parameters. The pre-treatments applied reduced the acrylamide content in French fries by 4–97% when fried in the pan and by 25–47% when fried in the fryer. Acrylamide content of French fries was negatively correlated with L* parameter and moisture content and positively correlated with a* parameter. The pre-treatments applied can be used successfully by consumers to reduce acrylamide content.

Effects of pulse electric field pretreatment on the frying quality and pore characteristics of potato chips

The main purpose of this work was to investigate the effect of pulsed electric field (PEF) treatment on the oil absorption capacity of potato chips, evaluated via changes to microstructure and pore characteristics. Our results showed that as electric field strength increased from 0 kV/cm (no pretreatment) to 5 kV/cm, the oil content of potato chips decreased by up to 20.6%. Furthermore, at higher the electric field strengths (5 ~ 20 kV/cm), most of the potato cell walls collapsed, and dense pores could be observed in the horizontal profile of the chips. Moreover, some smaller pores (10-50 nm) in the potato chips were disrupted and merged into larger pores (50-100 nm), thus increasing the total volume and average diameter of the pores, accelerating moisture evaporation and reducing oil absorption during frying. Our findings provide a novel perspective on the application of PEF towards the development of lower-fat and healthier fried foods.

Development of new strategy combining heat treatment and phage cocktail for post-contamination prevention

Heat treatment is an effective method for ensuring food safety and quality by controlling microbial contamination. However, food poisoning outbreaks have continuously occurred in heat-treated products due to improper thermal treatment and/or post-contamination of foodborne pathogens. This study proposes a novel strategy combining thermostable bacteriophages with thermal processing of food production plants to control foodborne pathogens and even bacterial contamination. Typically, bacteriophages' susceptibility to heat is a major challenge to their application with thermal processing, we isolated thermostable bacteriophages by a modified isolation method of applying heat to samples and characterized the thermostable bacteriophages. Furthermore, we optimized the bacteriophage cocktail components to expand the controllable host range and reduce the risk of bacteriophage resistance development. Finally, we verified this antibacterial strategy by combining heat treatment with thermostable bacteriophages in model systems, including milk and chicken breast. After the phage cocktail and heat treatment, we artificially contaminated the food products to mimic the post-contamination event. Surprisingly, the remaining bacteriophages that withstood heat treatment significantly reduced the number of post-contaminated Salmonella. Altogether, thermostable phages could be applied as complementary tools to control post-contamination after thermal processing of food products.

Recent advances in physical fields-based frying techniques for enhanced efficiency and quality attributes

Frying is one of the most common units in food processing and catering worldwide, which involves simultaneous physicochemical and structural changes. However, the problems of traditional frying technology, such as low thermal utilization and poor processing efficiency, have been gradually exposed to industrial production. In this paper, strategies of applying physical fields, such as pressure field, electromagnetic field, and acoustic field in frying technology separately or synergistically with improved efficiency and quality attributes are reviewed. The role of physical fields in the frying process was discussed with modifications in heat and mass transfer and porous structures. The effects of physical fields and their processing parameters on moisture loss kinetics, oil uptake, texture, color, and nutrients retention of fried food are introduced, respectively. Recent advances in multi-physical field-based frying techniques were recommended with synergistic benefits. Furthermore, the trends and challenges that could further develop the multi-physical field-based frying techniques are proposed, showing further commercial prospects for the purpose. The application of physical fields has brought new inspiration to the exploitation of efficient and high-qualified frying technologies, while higher technical levels and economic costs need to be taken into consideration. HighlightsThe role of physical fields in pretreatments and frying process were reviewed.The mechanism of physics fields on frying efficiency and quality was summarized.The physicochemical and microstructure changes by physics fields were discussed.The synergy of physical fields in frying technology were outlined.The trends for further multi-physical field-based frying techniques were proposed.

Food matrixes play a key role in the distribution of contaminants of lipid origin: A case study of malondialdehyde formation in vegetable oils during deep-frying

Vegetable oils are increasingly replacing animal fats in diets, but malondialdehyde (MDA), a peroxidation product of these oils, has been regarded as toxic; this necessitated investigation of MDA formation during consumption. This study investigated MDA formation in four vegetable oils during frying French fries (FF) and fried chicken breast meat (FCBM) at 180 °C for 7 h. Results showed that MDA contents were lower in oils used for frying foods than in control oils, mainly because MDA was incorporated into the foods. MDA content was lower in FF, but higher in FCBM, due to the different food components. Model oil and food system analyses yielded similar results. MDA bound the hydrophobic helical structure in starch-based FF, but was exhibited greater reactivity with nucleophilic groups in protein-based FCBM, resulting in stronger interaction with FCBM than with FF. Our results indicated the existence of distinct mechanisms underlying MDA migration in different food matrixes.

Optimization of the formula and processing of a sweet potato leaf powder-based beverage

For the development of a sweet potato leaf powder (SPLP)-based beverage, we investigated the effects of blanching methods on SPLP quality (including color, nutritional and functional compositions and antioxidant activity), and the effects of particle size and stabilizers on suspension stability of final product. The total polyphenol and antioxidant activity of SPLP of uncut group were 1.69 and 1.91 times those of cut group, respectively, and the indices of nutritional quality of copper, manganese and vitamin E of uncut group were significantly greater than cut group. The ultrafine SPLP-produced lowest gravitational sedimentation ratio (49%), indicating it had greatest suspension stability. The optimized formula of SPLP-based beverage was as follows: ultrafine SPLP of uncut group was mixed with 2.5% (w/w, powder basis) xanthan gum, 1% calcium lactate, 2% ascorbic acid, 12% maltodextrin, 20% xylitol, and 0.9% apple essence. The final product had high nutritional value along with consumer-acceptable flavor and texture.

Progress in research and applications of cassava flour and starch: a review

The cassava flours and starches have elicited great use in the food and non-food industry. The diversity in cassava genotypes accounts for differences in end-product properties, and would require characterization of cassava varieties for suitability of culinary and processing. This review showed that screening criteria of cassava cultivars end-user properties include proximate contents, amylose content, structural, swelling, gelatinization and pasting characteristics, including freeze-thaw stability properties of cassava-derived flours and starches. Literature shows that the physiochemical properties vary with genetic factors (i.e. genotype). In this review, the amylose content was found to be the main genetic trait for discriminating the cassava varieties for gelatinization and pasting processes including resistant starches. Moreover, cassava derived raw materials (flours and starches) were found to have various application in baking, edible film, syrup, glucose, alcohol, and soups production.

Matrix-mediated distribution of 4-hydroxy-2-hexanal (nonenal) during deep-frying of chicken breast and potato sticks in vegetable oil

The distribution of HHE/HNE was mediated in different food matrices, namely, starch-based and protein-based foods, during deep-frying of vegetable oils.