A. Heredia

Combined Drying Technologies for Development of High-Quality Shelf-Stable Mango Products

In this work, different combinations of osmotic dehydration followed by microwave-assisted hot air drying were studied for modeling and quality evaluation purposes. The results revealed that the two variables that most affected drying time of mango were the level of microwave power and osmotic dehydration time, rather than airflow velocity and temperature, which did not have an important influence until the final stage of drying. The results also revealed a nonuniform distribution of microwaves inside the dryer cavity that provoked the charring of pieces situated in a specific zone but an acceptable preservation of mango color after drying.

Mass Transfer and Volume Changes in French Fries During Air Frying

The production of healthier fried foods requires the adaptation of industrial processes. In this context, air frying is an alternative to deep oil frying to obtain French fries with lower fat content. Kinetic analysis of compositional changes and main fluxes involved in air frying were carried out, and the results were compared to those obtained for deep oil frying. The influence of the type of sample (unpretreated, frozen, or blanched potatoes) was also analyzed. The results showed that oil uptake is much lower in air frying although a much longer processing time is required. Also, water loss and thus the loss of volume were much higher in air frying compared to the conventional process.

Effect of Pretreatments and Air‐Frying, a Novel Technology, on Acrylamide Generation in Fried Potatoes

This paper investigated the effect of air-frying technology, in combination with a pretreatment based of soaking the samples in different chemical agent solutions (citric acid, glycine, calcium lactate, sodium chloride, or nicotinic acid [vitamin B3]), on the generation of acrylamide in fried potatoes. The influence of reducing sugars on the development of surfaces color was also analyzed. The experiments were conducted at 180 °C by means of air-frying and deep-oil-frying, as a reference technology. Based on the evolution of color crust with frying time, it could be concluded that the rate of Maillard reaction decreased as the initial reducing sugars content increased in the raw material, and was also lower for deep-oil-frying than for air-frying regardless of pretreatments applied. Air-frying reduced acrylamide content by about 90% compared with conventional deep-oil-frying without being necessary the application of a pretreatment. However, deep-oil fried potatoes pretreated with solutions of nicotinic acid, citric acid, glycine at 1%, and NaCl at 2% presented much lower acrylamide levels (up to 80% to 90% reduction) than nonpretreated samples.Authors would like to thank Generalitat Valenciana (GV/2012/072) for the financial support given to this investigation.

Influence of processing on the volatile profile of strawberry spreads made with isomaltulose

A new strawberry spread formulated with fructose and isomaltulose (replacing sucrose partially or totally) and a high percentage of fruit was developed in line with the new trend of healthier products. This work studies the influence of some process variables (percentage of sugar, pectin and citric acid, and time of thermal treatment) on the volatile profile of these spreads with different formulations. The ripeness of the raw strawberries influences the concentrations of some of the compounds in the spreads, such as isobutyl acetate, butyl butyrate, 3-hexen-1-yl acetate or propan-2-ol. The process conditions have an important effect on the volatile profiles. Most of the esters and alcohols decreased whereas 13 new compounds appear, mostly furans (furfural, 2-acetylfurane, 5-methyl furfural, mesifurane) and aldehydes (octanal, nonanal, decanal and benzaldeyhde). In general, the spreads formulated with sucrose-isomaltulose that contained higher levels of pectin and citric acid gave better results in the preservation of the original aromatic compounds in raw strawberries.

Influence of thermal treatment and storage on astringency and quality of a spreadable product from persimmon fruit

The aim of this work was to develop osmodehydrated products from cubes of persimmon (var. Rojo Brillante), which could be spread as a jam but keeping the typical aroma, flavour and colour of fresh fruit. The application of a thermal treatment in the filling stage has been studied, with or without a later pasteurisation step at 90°C for 20min. These spreadable products were stored at room temperature or in refrigeration. The chemical composition, pH, aw, colour, astringency, antioxidant capacity and the growth of yeast, moulds and aerobic mesophiles were analysed after the manufacture process and throughout the storage (approximately 3.5months). Sensorial analyses were also performed after 24h of being prepared and after 49days of refrigeration. The product obtained without thermal treatment was the best since it maintained the characteristic persimmon colour better and showed higher antioxidant capacity. Furthermore, it was the best, according to the panel, not only for appearance but also for flavour.

Evaluation studies of persimmon plant (Diospyros kaki) for physiological benefits and bioaccessibility of antioxidants by in vitro simulated gastrointestinal digestion.

This study aims to analyze the antioxidant benefits from persimmon leaf tea, fruit and fibres taking into account their changes along gastrointestinal digestion. The evolution of polyphenols, flavonoids and antioxidant capacity was studied using the recent harmonized in vitro protocol published by Minekus et al. (2014). The digestion was performed with and without digestive enzymes. Results showed aqueous leaf extract was richer in antioxidants than the fruit or the extracted fibres. Nevertheless, persimmon-leaf antioxidants were more sensitive to the digestive environment. In general, the oral conditions greatly affected the antioxidants, while gastric digestion led to slight additional losses. The intestinal step enhanced polyphenols and flavonoids solubility coming from the fruit and fibres. Additionally, the presence of digestive enzymes positively contributed to antioxidant release throughout digestion. Finally, the bioaccessibility of polyphenols, flavonoids and antioxidant activity of persimmon fruit were 1.4, 1.0 and 3.8 times higher than in aqueous leaf extract.

Dietary acrylamide: What happens during digestion

Acrylamide is a well-known potentially carcinogen compound formed during thermal processing as an intermediate of Maillard reactions. Three objectives were addressed: the impact of gastric digestion on acrylamide content of French Fries, chips, chicken nuggets, onions rings, breakfast cereals, biscuits, crackers, instant coffee and coffee substitute; the acrylamide content evolution during gastrointestinal digestion of French fries and chips; and the effectiveness of blanching and air-frying on acrylamide mitigation after gastrointestinal digestion. A significant increase (p-value <0.05) in acrylamide content was observed for most of the products after gastric digestion (maximum registered for sweet biscuits, from 30±8 to 150±48µg/kg). However, at the end of the intestinal stage, acrylamide values were statistically similar (p-value=0.132) for French fries and lower than the initial values (before digestion) in potato chips (p-value=0.027). Finally, the low acrylamide content found in blanched and air-fried samples, remained still lower than for deep fried samples even after gastrointestinal digestion.

Mathematical Equations to Predict Mass Fluxes and Compositional Changes During Osmotic Dehydration of Cherry Tomato Halves

Cherry tomato halves (L. esculentum var. Cerasiforme cv. Cocktail) were dehydrated by immersion in binary solutions of salt or sugar and ternary salt-sugar solutions at 30, 40, and 50°C. Compositional changes (moisture, sugar, and salt content) as well as mass fluxes were controlled at different process times. The influence of temperature and osmotic agents (salt, sucrose, and the combination of them) on mass transfer phenomena was studied, and the experimental results were modeled in order to establish a set of equations that would facilitate the prediction not only of final product composition, which is related to its quality and its stability, but also the mass fluxes involved in the process associated to the yield of the process.

In Vitro Digestion of Lipids in Real Foods: Influence of Lipid Organization Within the Food Matrix and Interactions with Nonlipid Components: In vitro digestion of lipids in foods…

Abstract In vitro digestion research has scarcely addressed the assessment of the complexity of digestion in real food. The aim of the present study was to evaluate the influence of intestinal conditions, nonlipid components, and lipid organization within the food matrix on lipolysis extent. A selection of 52 foods was studied under different simulated intestinal conditions, including those related to patients with cystic fibrosis (pH6, bile salts 1 mM due to decreased pancreatic and biliary secretions) and to healthy subjects (pH7, bile salts 10 mM). Linear mixed regression models were applied to explain associations of food properties with lipolysis. Normal intestinal conditions allowed for optimal lipolysis in most of the foods in contrast to the altered intestinal scenario (30 compared with 1 food reaching > 90% lipolysis). Lipid‐protein and lipid‐starch interactions were evidenced to significantly affect lipolysis (P < 0.001) in all the digestion conditions, decreasing in those foods with low fat and high protein or high starch content. In addition, under decreased intestinal pH and bile concentration, lipolysis was lower in foods with complex solid structures and continuous lipid phase than in the oil‐in‐water continuous aqueous phase (global P < 0.01). However, in the normal conditions lipid organization within the food matrix did not show a significant effect on lipolysis (global P = 0.08). In conclusion, food properties play a crucial role in lipolysis, which should be considered when establishing dietary recommendations. Practical Application Food composition, lipid organization within the food matrix, and gastrointestinal conditions are key factors affecting lipolysis. Knowledge on that can be used to modulate lipolysis performance after food ingestion. Different applications are foreseen, as food design and nutritional recommendations for the general populations and specific target groups. The most immediate application is related to the scope of the research project that frames this work (http://www.mycyfapp.eu). These results have contributed to the development of a mobile app for cystic fibrosis patients, which includes an algorithm for enzyme dose prediction based on food properties. The app is currently being tested in a clinical trial setting.

Effect of saffron (Crocus sativus L.) enrichment on antioxidant and sensorial properties of wheat flour pasta

Saffron, used in cookery as a flavouring and colouring agent, is well-known for its antioxidant and beneficial health properties. In the present work, the effect of saffron addition (0-control, 0.1, 0.2 and 0.4%, w/w) in the formulation of fresh pasta was evaluated on textural, physical-chemical, and sensory properties of the cooked product. Content and retention of the bioactive molecules of saffron (crocins) were evaluated by HPLC along with the corresponding antioxidant activity of enriched pasta. The presence of saffron significantly influenced textural and physical-chemical properties of pasta. Higher saffron concentrations enhanced the antioxidant activity of pasta with the higher values of crocins in samples enriched with 0.4% saffron extract even after 3 min of cooking (4.23-5.06 mg/g db). Sensory analysis showed an increased acceptability of the saffron enriched pasta for all descriptors selected (visual aspect, colour, aroma, taste, chewiness, hardness, gumminess and overall acceptability).