Analysis of Maillard reaction precursors and secondary metabolites in Chilean potatoes and neoformed contaminants during frying.

Southern Chile native potatoes are an interesting raw material to produce novel snacks like colored potato chips. These novel products should be comprehensively evaluated for the presence of undesirable compounds such as acrylamide, 5-hydroxymethylfurfural and furan, the main neoformed contaminants in starchy rich fried foods. This study evaluated the neoformed contaminant levels and oil content on chips made from eleven Chilean potato accessions and compared them with commercial samples. The neoformed contaminant contents were related to Maillard reaction precursor levels (reducing sugars and asparagine) and secondary metabolites (phenolic compounds and carotenoids). Neoformed contaminants correlated well among them and were weakly correlated with reducing sugars and asparagine. Acrylamide level in native potato chips ranged from 738.2 to 1998.6 µg kg-1 while from 592.6 to 2390.5 µg kg-1 in commercial samples. Thus, there is need to implement neoformed contaminant mitigation strategies at different steps of the production chain of colored potato chips.

Integrated effect of yeast inoculation and roasting process conditions on the neo formed contaminants and bioactive compounds of Colombian roasted coffee (Coffea arábica).

The rational design of methodologies to control the neoformed compounds occurrence (NFCs), such as acrylamide and hydroxymethylfurfural (HMF) in roasted coffee, must consider the preservation of the bioactive compounds contained in this beverage. The aim of this work was to evaluate the integrated effect of yeast inoculation during the fermentation stage and the modification of roasting parameters on the final concentrations of NFCs and bioactive compounds of roasted coffee. A completely randomized factorial design was used to evaluate the effect of yeast inoculation (with and without inoculation), roasting temperature (150, 180 and 210 °C) and roast degree (medium, dark) on the (i) physicochemical characteristics (volume change, mass loss, water activity, non-enzymatic browning index, antioxidant capacity, total polyphenols, chlorogenic acid and caffeine) as well as HMF and acrylamide levels of roasted coffee. Response variables were analyzed separately by ANOVA and clustering of treatments was explored by PCA. Yeast inoculation did not significantly (p > 0.05) affect volume change, mass loss, antioxidant capacity, total polyphenols content, and caffeine contents. The interaction of evaluated factors significantly decreased (p < 0.05) the acrylamide and HMF contents of roasted coffee (43 % and 56.0 %, respectively). Based on PCA grouping the best treatments were medium roast at 210 °C (inoculated and uninoculated) and at 180 °C (inoculated). Under these conditions it is possible to produce a roasted coffee mitigated in neo formed contaminants that present the physicochemical properties of original product.

Effect of the Integrated Addition of a Red Tara Pods (Caesalpinia spinosa) Extract and NaCl over the Neo-Formed Contaminants Content and Sensory Properties of Crackers.

A 2k factorial design with three centrals points was considered to evaluate the effect of adding red Tara pods extract (Caesalpinia spinosa) (440-2560 µg/mL of dough water) and NaCl (0.3-1.7 g/100 g of flour) on the acrylamide (AA) and hydroxymethylfurfural (HMF) content and sensory attributes of crackers. Additionally, the best formulation, defined as that with the lowest AA and HMF content, was compared with a commercial formulation cracker. Red Tara pods extracts were obtained through conventional extraction using pure water (60 °C, 35 min). AA and HMF content were quantified by GC-MS and HPLC-DAD, respectively. The sensory evaluation was carried out using a descriptive analysis on a 10 cm non-structured linear scale. Red Tara pods extract significantly reduced (p < 0.05) the AA and HMF content, while NaCl only influenced the HMF formation. However, the sensory attributes did not significantly change (p > 0.05), excepting the violet-gray color and salty flavor, but at acceptable levels compared with the control sample. The higher the red Tara pods extract concentration (2560 µg/mL of dough water), the lower the neo-formed contaminants (NFCs) content of crackers (AA: 53 µg/kg and HMF: 1236 µg/kg) when salt level was below 3 g/100 g of flour. The action of the proanthocyanidins present in the extracts which trapped the carbonyl groups of sugars probably avoided the formation of both NFCs. Contrarily, NaCl addition (from 0.3 to 1.7 g/100 g of flour) significantly increased (p < 0.05) the HMF formation (from 1236 µg/kg to 4239 µg/kg, respectively), probably through the dehydration of carbohydrates during the Maillard reaction. When explored treatments were compared with a commercial formulated cracker, the highest mitigation effect (reductions of 40% and 32% AA and HMF, respectively) was reached with the addition of 2560 µg/mL of dough water of red Tara pods extract and 0.3 g/100 g of flour of NaCl. The addition of red Tara pods extracts integrated with the control of NaCl levels mitigated the NFCs in crackers, preserving their sensory properties. Future research should be focused on scaling this mitigation technology, considering a better chemical characterization of red Tara pods extracts as well as the validation of its use as functional food ingredient.

Pressurized Hot Liquid Extraction with 15% v/v Glycerol-Water as An Effective Environment-Friendly Process to Obtain Durvillaea incurvata and Lessonia spicata Phlorotannin Extracts with Antioxidant and Antihyperglycemic Potential.

Brown seaweed phlorotannins have shown the potential to promote several health benefits. Durvillaea incurvata and Lessonia spicata-species that are widely distributed in central and southern Chile-were investigated to obtain phlorotannin extracts with antioxidant and antihyperglycemic potential. The use of an environmentally friendly and food-grade glycerol-based pressurized hot liquid extraction (PHLE) process (15% v/v glycerol water) was assessed for the first time to obtain phlorotannins. Multiple effects were analyzed, including the effect of the species, harvesting area (Las Cruces and Niebla), and anatomical part (holdfast, stipe, and frond) on the extracts' polyphenol content (TPC), antioxidant capacity (AC), and carbohydrate-hydrolyzing enzyme-α-glucosidase and α-amylase-inhibitory activity. Contaminants, such as mannitol, heavy metals (As, Cd, Pb, Hg, and Sn), and 5-hydroxymethylfurfural (HMF), were also determined. The anatomical part used demonstrated a significant impact on the extracts' TPC and AC, with holdfasts showing the highest values (TPC: 95 ± 24 mg phloroglucinol equivalents/g dry extract; DPPH: 400 ± 140 µmol Trolox equivalents/g dry extract; ORAC: 560 ± 130 µmol TE/g dry extract). Accordingly, holdfast extracts presented the most potent α-glucosidase inhibition, with D. incurvata from Niebla showing an activity equivalent to fifteen times that of acarbose. Only one frond and stipe extract showed significant α-glucosidase inhibitory capacity. No α-amylase inhibition was found in any extract. Although no HMF was detected, potentially hazardous cadmium levels (over the French limit) and substantial mannitol concentrations-reaching up to 50% of the extract dry weight-were found in most seaweed samples and extracts. Therefore, further purification steps are suggested if food or pharmaceutical applications are intended for the seaweed PHLE extracts obtained in this study.

Is the dietary acrylamide exposure in Chile a public health problem?

This study estimates for the first time dietary acrylamide intake in Chile and conducts exposure risk assessments using the margin of exposure (MOE) method. A consumption frequency survey of starchy foods was carried out in the metropolitan region of Santiago, Chile on people from different socioeconomic levels aged between 12 and 65 years old. The acrylamide contents of the most frequently consumed foods were determined by an in-house validated GC-MS technique. The potatoes and bread group contributed ~77% to the dietary acrylamide exposure in Chile, with estimated daily mean exposure of 0.55 µg kgbw-1 day-1 and 0.22 µg kgbw-1 day-1, respectively. Chilean population aged between 12 and 17 years old presented the highest acrylamide intake (mean, 1.27 µg kgbw-1 day-1; 95th percentile, 3.90 µg kgbw-1 day-1). Finally, since the estimated MOEs were lower than 10,000, the dietary acrylamide exposure in the metropolitan region of Santiago, Chile is of public health concern according to the EFSA criteria.

The Impact of Temperature and Ethanol Concentration on the Global Recovery of Specific Polyphenols in an Integrated HPLE/RP Process on Carménère Pomace Extracts.

Sequential extraction and purification stages are required to obtain extracts rich in specific polyphenols. However, both separation processes are often optimized independently and the effect of the integrated process on the global recovery of polyphenols has not been fully elucidated yet. We assessed the impact of hot-pressurized liquid extraction (HPLE) conditions (temperature: 90-150 °C; ethanol concentration: 15%-50%) on the global recovery of specific phenolic acids, flavanols, flavonols and stilbenes from Carménère grape pomace in an integrated HPLE/resin purification (RP) process. HPLE of phenolic acids, flavanols and stilbenes were favored when temperature and ethanol concentration increased, except for chlorogenic acid which showed an increment of its Gibbs free energy of solvation at higher ethanol contents. Ethanol concentration significantly impacted the global yield of the integrated HPLE/RP process. The lower the ethanol content of the HPLE extracts, the higher the recovery of phenolic acids, flavanols and stilbenes after RP, except for flavonols which present more polar functional groups. The best specific recovery conditions were 150 °C and ethanol concentrations of 15%, 32.5% and 50% for phenolic acids, flavanols and stilbenes, and flavonols, respectively. At 150 °C and 32.5% of ethanol, the extracts presented the highest total polyphenol content and antioxidant capacity. The integrated HPLE/RP process allows a selective separation of specific polyphenols and eliminates the interfering compounds, ensuring the safety of the extracts at all evaluated conditions.

Predicting furan content in a fried dough system using image analysis.

The aim of this paper is to test different models for predicting furan content in a dough system, based on partial least squares regression using colour images. Starch dough systems were fried at five temperatures between 150 and 190 °C and for 5, 7, 9, 11 and 13 min. The furan content was quantified using gas chromatography/mass spectrometry, while the corresponding images were simultaneously obtained and processed in order to extract 2914 features. Good furan content predictions were obtained using computer vision image chromatic features using correlation coefficient of prediction (Rp = 0.86). However, the best prediction correlation was obtained using the image textural features (Rp = 0.93), when the number of features was reduced to 10 by algorithms applications. These results suggest that furan content in fried dough systems can be predicted using features of computer vision images.

Effect of formulation and baking conditions on the structure and development of non-enzymatic browning in biscuit models using images.

The aim of this research was to determine the effect of composition (dietary fiber = DF, fat = F, and gluten = G) and baking time on the target microstructural parameters that were observed using images of potato and wheat starch biscuits. Microstructures were studied Scanning Electron Microscope (SEM). Non-enzymatic browning (NEB) was assessed using color image analysis. Texture and moisture analysis was performed to have a better understanding of the baking process. Analysis of images revealed that the starch granules retained their native form at the end of baking, suggesting their in complete gelatinization. Granules size was similar at several different baking times, with an average equivalent diameter of 9 and 27 µm for wheat and potato starch, respectively. However, samples with different levels of DF and G increased circularity during baking to more than 30%, and also increasing hardness. NEB developed during baking, with the maximum increase observed between 13 and 19 min. This was reflected in decreased luminosity (L*) values due to a decrease in moisture levels. After 19 min, luminosity did not vary significantly. The ingredients that are used, as well as their quantities, can affect sample L* values. Therefore, choosing the correct ingredients and quantities can lead to different microstructures in the biscuits, with varying amounts of NEB products.

Statistical pattern recognition classification with computer vision images for assessing the furan content of fried dough pieces.

This research tested furan classification models in fried matrices based on the pattern recognition of images. Samples were fried at 150, 160, 170, 180, and 190°C for 5, 7, 9, 11, 13, and 30min. Furan was measured by GC-MS. Corresponding images were acquired and processed to extract 2175 chromatic and textural features. Principal component analysis was used to reduce features to 8-12 principal components. In parallel, sequential forward selection coupled with linear discriminant analysis (LDA) was the best strategy to select only 5-7 features. LDA was the best classifier with 91.39-97.60% recognizing above 113µg/kg and 69.54-83.80% to classify images from class 1 (0-38µg/kg) from class 2 (39-113µg/kg). Also, support vector machine recognized 87.71-96.74% of class 3 (114-398µg/kg) from class 4 (399-646µg/kg). The technique may be used to detect high amount of furan in fried starchy matrices.

The Antioxidant and Safety Properties of Spent Coffee Ground Extracts Impacted by the Combined Hot Pressurized Liquid Extraction-Resin Purification Process.

Hot pressurized liquid extraction has been used to obtain polyphenols; however, its operating conditions can generate hydroxymethylfurfural, a potential human carcinogen. The addition of ethanol can reduce process temperatures and retain extraction efficiencies, but the ethanol may reduce the recovery of polyphenols in the subsequent purification stage, affecting the antioxidant properties of the extracts. This study evaluates a combined hot pressurized liquid extraction-resin purification process to obtain polyphenol extracts from spent ground coffee reduced in hydroxymethylfurfural. A multifactorial design was developed to determine the combined effect of the extraction (ethanol content: 0-16% and temperature: 60-90 °C) and purification (ethanol: 60-80%) conditions on some chemical properties of the extracts. The highest recovery of polyphenols (~8 mg GAE/g dry coffee solids) and reduction of hydroxymethylfurfural (95%) were obtained at 90 °C and 16% of ethanol during extraction and 80% of ethanol during purification. These operating conditions retained the antioxidant capacity of the crude extract between 60% and 88% depending on the determination method and recovered 90, 98, and 100% of 4-feruloylquinic acid, epicatechin, and 5-feruloylquinic acid, respectively after purification. The combined process allows differential polyphenols' recovery and enhances the safety of the extracts. Our computational chemistry results ruled out that the overall selectivity of the integrated process was correlated with the size of the polyphenols.

A Kinetic Study of Furan Formation in Wheat Flour-Based Model Systems during Frying.

Furan is a possible human carcinogen, which is formed in worldwide highly consumed fried starchy foods. In order to elucidate the mechanisms responsible for its occurrence in this food category and propose techniques for its mitigation, the kinetics of furan formation, oil absorption, lipid oxidation, and color change were studied in wheat flour-based model systems during frying at 160, 170, 180, and 190 °C up to 13 min and data were fitted to mathematical models. Additionally, an Arrhenius-type dependency with temperature was evaluated for all studied responses. More drastic frying conditions increased significantly (P ≤ 0.05) the furan content of fried samples. Furan formation followed a sigmoid trend with frying time only for frying temperature of 190 °C (RMS190°C : 7.6%). At lower temperatures, furan generation did not reach the asymptotic concentration level. Color change, lipid oxidation, and oil absorption increased with frying temperature and followed asymptotic relationships with frying time. For all evaluated temperatures, color change (RMS: 4.4% to 12.5%) and polar compound generation (RMS: 2.6% to 7.4%) presented good fit to a first-order kinetic model. Oil absorption was successfully fit to a mass balance-based model (RMS: 10.0% to 19.8%). Under the experimental conditions studied, only color change (EA : 15.47 kJ/mol), lipid oxidation (EA : 6.67 kJ/mol), and oil absorption (EA : 76.98 kJ/mol) presented good fit (RMS: 0.7% to 6.3%) to an Arrhenius-type equation. Based on our results, the keeping of frying temperature below 180 °C and the reduction of the frying time would contribute to reduce not only the final furan occurrence in fried foods but also their oil content.

Physical properties of emulsion-based hydroxypropyl methylcellulose/whey protein isolate (HPMC/WPI) edible films.

The objective of this research was to study the effect of the film microstructure of oil-in-water emulsions stabilized by hydroxypropyl methyl cellulose/whey protein isolate (HPMC/WPI) with or without sodium dodecyl sulfate (SDS) over physical properties of HPMC/WPI emulsion-based films. The films were prepared with different HPMC/WPI-oil-SDS combinations (%w/w for 100g of dispersion): HPMC; WPI; HPMC/1WPI-0.5-SDS; HPMC/1WPI-1; HPMC/2WPI-0.5; HPMC/2WPI-1-SDS. Physical properties of films were evaluated. The results showed no statistical differences (p>0.05) between the thicknesses of EFs (0.156 ± 0.004 mm). The effect of oil content and incorporation of SDS showed the inverse trend for WI and ΔE, the increasing order of change, for WI and ΔE, among the formulation evaluated was: HPMC/1WPI-1>HPMC/2WPI-0.5>HPMC/2WPI-1.0-SDS≈HPMC/1WPI-0.5-SDS≈WPI>HPMC for WI and HPMC/1WPI-0.5-SDS>HPMC/2WPI-1.0-SDS>HPMC/2WPI-0.5>HPMC/1WPI-1 for ΔE, respectively. The addition of oil and SDS decreased the TS and EB, because oil addition into EF induces the development of structural discontinuities, producing an EF with less chain mobility, and consequently, with less flexibility and resistance to fracture.

Current issues in dietary acrylamide: formation, mitigation and risk assessment.

Acrylamide (AA) is known as a neurotoxin in humans and it is classified as a probable human carcinogen by the International Agency of Research on Cancer. AA is produced as by-product of the Maillard reaction in starchy foods processed at high temperatures (>120 °C). This review includes the investigation of AA precursors, mechanisms of AA formation and AA mitigation technologies in potato, cereal and coffee products. Additionally, most relevant issues of AA risk assessment are discussed. New technologies tested from laboratory to industrial scale face, as a major challenge, the reduction of AA content of browned food, while still maintaining its attractive organoleptic properties. Reducing sugars such as glucose and fructose are the major contributors to AA in potato-based products. On the other hand, the limiting substrate of AA formation in cereals and coffee is the free amino acid asparagine. For some products the addition of glycine or asparaginase reduces AA formation during baking. Since, for potatoes, the limiting substrate is reducing sugars, increases in sugar content in potatoes during storage then introduce some difficulties and potentially quite large variations in the AA content of the final product. Sugars in potatoes may be reduced by blanching. Levels of AA in different foods show large variations and no general upper limit is easily applicable, since some formation will always occur. Current policy is that practical measures should be taken voluntarily to reduce AA formation in vulnerable foods since AA is considered a health risk at the concentrations found in foods.

Are Chileans exposed to dietary furan?

Chilean consumer preferences include foods that may contain considerable amounts of furan, a potential human carcinogen. However, there is no information regarding dietary exposure to furan in Chile. Thus, the objective of this work was to determine the Chilean exposure to dietary furan. To accomplish this objective, the furan concentration of 14 types of commercial foods processed at high temperature were analysed based on a modified headspace-GC/MS (HS-GC/MS) method in which the limits of detection for different food matrices ranged from 0.01 to 0.6 ng g(-1). In addition, a risk assessment was made with exposure estimates based on dietary data from national studies on different age groups (9-month-old babies, school children, adults and elderly people). Of the food items surveyed "American"-type coffee (espresso coffee plus hot water) obtained from automatic coffee machine (936 ng g(-1)) and low moisture starchy products like crisps and "soda"-type crackers showed the highest furan concentrations (259 and 91 ng g(-1), respectively). Furthermore, furan was also found in samples of breakfast cereals (approximately 20 ng g(-1)), jarred fruit baby foods (8.5 ng g(-1)) and orange juice (7.0 ng g(-1)). School children (aged 9-13 years) represented the highest intake of furan (about 500 ng kg(-1)(bw) day(-1)), with margins of exposure of 2479 and 2411, respectively, which points to a possible public health risk.

Furan: a critical heat induced dietary contaminant.

The presence of furan in a broad range of heat processed foods (0-6000 µg kg(-1)) has received considerable attention due to the fact that this heat induced contaminant is considered as a "possible carcinogenic compound to humans". Since a genotoxic mode of action could be associated with furan-induced tumor formation, current human exposure levels to this contaminant may indicate a risk to human health and the necessity for its mitigation. This review summarizes and focuses on the main issues of furan toxicity, human dietary exposure to furan and mechanisms of furan formation. Additionally, the role of some critical factors such as heating conditions, pH and matrix microstructure are discussed in order to propose some potential methodologies for furan mitigation in a wide range of heated foods.

Furan occurrence in starchy food model systems processed at high temperatures: effect of ascorbic acid and heating conditions.

Furan, a potential carcinogen, has been detected in highly consumed starchy foods, such as bread and snacks; however, research on furan generation in these food matrixes has not been undertaken, thus far. The present study explored the effect of ascorbic acid addition and cooking methods (frying and baking) over furan occurrence and its relation with the non-enzymatic browning in a wheat flour starchy food model system. Results showed that furan generation significantly increased in the presence of ascorbic acid after 7 min of heating (p < 0.05). The strongest effect was observed for baked products. Additionally, the furan content in fried products increased with the increase of the oil uptake levels. As for Maillard reactions, in general, the furan level in all samples linearly correlated with their degree of non-enzymatic browning, represented by L* and a* color parameters (e.g., wheat flour baked samples showed a R(2) of 0.88 and 0.87 for L* and a*, respectively), when the sample moisture content decreased during heating.

Patented techniques for acrylamide mitigation in high-temperature processed foods.

Heating foods has many advantages since it adds taste, color, texture and minimizes harmful germs, among others. Flavor and aroma compounds are produced via the Maillard reaction, where various hazardous compounds may form as well, such as acrylamide. Maillard reaction is believed to be the main route for acrylamide formation between reducing sugars (glucose and fructose), sucrose, and the amino acid asparagine, and, consequently, a variety of technologies have been developed to reduce acrylamide concentration in thermally processed foods based either on: (i) Changing process parameters (e.g. time and temperature of cooking) which inhibits Maillard Reaction; (ii) Reducing acrylamide precursor levels in raw materials to be cooked at high temperatures (e.g. by using microorganisms, asparaginase, amino acids and saccharides, blanching, etc.). In this paper, most of the recent patents for acrylamide reduction in foods processed at high temperatures are mentioned and briefly analyzed in order to develop new mitigation techniques for acrylamide in different food matrixes.

The effect of asparaginase on acrylamide formation in French fries.

Acrylamide formation in French fries was investigated in relation to blanching and asparaginase soaking treatments before final frying. Par-fried potatoes of Bintje variety were prepared by cutting strips (0.8×0.8×5cm) which were blanched at 75°C for 10min. Unblanched strips were used as the control. Control or blanched strips were then dried at 85°C for 10min and immediately partially fried at 175°C for 1min. Finally, frozen par-fried potatoes were fried at 175°C for 3min to obtain French fries. Pre-drying of raw or blanched potato strips did not generate acrylamide formation as expected. Partial frying of pre-dried control potato strips generated 370µg/kg of acrylamide and the final frying determined French fries with 2075µg/kg of acrylamide. When control potato strips were treated with a 10000 ASNU/l asparaginase solution at 40°C for 20min, the acrylamide formation in French fries was reduced by 30%. When blanched potato strips were treated in the same way, the produced French fries have 60% less acrylamide content than blanched strips without the enzyme treatment. Soaking of blanched potato strips (75°C, 10min) in an 10000 ASNU/l asparaginase solution at 40°C for 20min is an effective way to reduce acrylamide formation after frying by reducing the amount of one of its important precursors such as asparagine.