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Snacks represent a food that has gained great popularity due to changes in lifestyles in recent years and to the fact that many people now have less time to spend eating. There are different kinds of snack products which may be classified according to: (i) raw materials used in their production (vegetables, fruits, restructured dough, etc.) and (ii) unit operations used for their manufacture (frying, baking, extrusion, roasting, etc.). Potato crisps are the star product among the commercial snacks. This article briefly discusses the main quality characteristics of potato snacks, giving an overview of the most important aspects of their production and quality attributes. Current challenges in snack industry focus on producing healthier snacks (reducing the amount of fat, sodium and sugar, principally) without losing the typical quality characteristics of these products.

Heating foods immersed in oil during frying provides many attractive sensorial attributes including taste, flavor and color. However, some toxic compounds formed during frying of potatoes such as furan and acrylamide may constitute an increased cancer risk for consumers. The objective of this work was to mitigate the furan and acrylamide formation in potato chips without increasing their oil uptake by optimizing the blanching treatment before final frying. Potato slices were blanched in order to simultaneously leach out ascorbic acid and reducing sugars, the most important precursors of furan and acrylamide generation in thermally treated starchy foods. A central composite design was implemented to optimize the temperature-time blanching conditions under which furan, acrylamide and oil content in potato chips were minimized. The optimum blanching conditions were 64 °C and 17 min in which significant reductions of furan, acrylamide and oil content (91%, 54% and 19% respectively) were reached.

Acrylamide (AA) (CAS number 79-06-1) (CH2=CH–CO–NH2), a white, odorless, toxic crystalline compound is produced mainly for the synthesis of nontoxic polyacrylamide, which is used as a flocculent in water treatment, and as a binder in pulp and paper processing. AA affects the nervous system even at low levels, causing hallucinations and drowsiness (IARC 1994). Human health effects associated with consumption of small amounts of AA over long periods of time are not known (Bent et al. 2012). AA vapors irritate the eyes and skin and cause paralysis of the cerebrospinal system (Kotsiou et al. 2011). Chronic exposure results in neurotoxicity in animals and humans, and AA has been found to be carcinogenic to laboratory animals. As a result, AA has been classified as “probably carcinogenic to humans” (Group 2A) by the International Agency for Research on Cancer (IARC 1994).

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.

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.

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.

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 (RMS

Potato processing is highly industrialized, technologically advanced, and very market-driven. However, the quality of its products and the economic success of this industry highly depend on available raw materials: namely, the potatoes. Deep fat frying is a complex unit operation that induces significant microstructural changes in potato tissue; in fact, most desirable characteristics of fried foods are derived from the formation of a composite structure: (1) a dry, porous, crispy, and oily outer layer or crust; and (2) a moist cooked interior or core whose microstructures have formed during the process. On the other hand, when potatoes are cooked immersed in hot water (temperature ≤ 100 °C), no crust is formed and principally microstructural changes in potato tissue such as starch gelatinization and lamella media solubilization occur and end with a final microstructure similar to that present in the core of a french fry (moist cooked interior).

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.

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.

The occurrence of furan in home cooked food was studied. Cooking was found to reduce the level of furan in ready-to-eat foods, however on average around 50% of furan remain in the foods. The analysis of furan occurrence revealed that it is most commonly formed in foods with high levels of carbohydrates. Interestingly, breakfast cereals, dry bread products, and dried fruit products including raisins, plums and bananas contained furan at levels up to 387 mu g/kg. Furan was also found in the dry ingredients of cookies and bread, and in snacks such as crisps and popcorn. The 2-alkylfurans, 2-methylfuran, 2,5-dimethylfuran, 2-ethylfuran, and 2-pentylfuran were present at levels in the same range as furan (885 mu g/kg) and the level of 2-methylfuran (1328 mu g/kg) exceeded this level in coffee.