Isabel Escriche

Use of vacuum impregnation in food salting process

Salting is an ancient preservation method, usually used separately or in combination with other processes such as air drying and pH lowering. Traditional salting processes are divided into brining and dry salting, each of them specifically applied for particular products. In this work, the use of brine vacuum impregnation (BVI) instead of dry salting or brine immersion (BI) at atmospheric pressure is discussed. The influence of different process variables (length of vacuum pressure period, temperature, sample structure and dimensions) is analysed, in terms of kinetic data and process yields, for meat (ham and tasajo), fish (salmon and cod) and cheese (Manchego type cheese). In general, BVI processes imply a notable reduction of salting time, increasing the process yields in line with the greater values of the ratio salt gain to water loss. Likewise, samples lose natural gas or liquid phases entrapped in their structure and reach a flatter salt concentration profile than that obtained in the conventional salting methods.

Antioxidants: Characterization, natural sources, extraction and analysis

Recently many review papers regarding antioxidants from different sources and different extraction and quantification procedures have been published. However none of them has all the information regarding antioxidants (chemistry, sources, extraction and quantification). This article tries to take a different perspective on antioxidants for the new researcher involved in this field. Antioxidants from fruit, vegetables and beverages play an important role in human health, for example preventing cancer and cardiovascular diseases, and lowering the incidence of different diseases. In this paper the main classes of antioxidants are presented: vitamins, carotenoids and polyphenols. Recently, many analytical methodologies involving diverse instrumental techniques have been developed for the extraction, separation, identification and quantification of these compounds. Antioxidants have been quantified by different researchers using one or more of these methods: in vivo, in vitro, electrochemical, chemiluminescent, electron spin resonance, chromatography, capillary electrophoresis, nuclear magnetic resonance, near infrared spectroscopy and mass spectrometry methods.

Effect of blanching/osmotic dehydration combined methods on quality and stability of minimally processed strawberries

Abstract The combined effect of blanching [steam (S) or microwave (MW)] and osmotic dehydration at atmospheric pressure (OD) or pulsed vacuum treatments (PVOD), on some physiochemical and quality parameters of strawberry (aw, pH, color, firmness, polyphenoloxidase enzyme activity and microstructure), as well as on microbial stability of processed samples, was analyzed. Pulsed vacuum osmotic dehydration with 65 Brix sucrose solution of strawberry, carried out after steam blanching treatment was the most effective in aw depression due to the highest sucrose gain during osmotic treatment. This implies the highest loss of firmness and color changes, but at the same time it induce the greatest microbial stability. CryoSEM observations shows that, steam treated samples suffer a great degree of cell decompartmentation near the fruit skin, as compared with the well preserved cells in MW treated samples. Differences in microstructural features observed between OD and PVOD treated samples were not reflected on the measured mechanical parameters.

Suitability of antioxidant capacity, flavonoids and phenolic acids for floral authentication of honey. Impact of industrial thermal treatment

Total antioxidant activity, physicochemical parameters, and the profile of flavonoids and phenolic acid compounds were evaluated for: their ability to distinguish between the botanical origins of four types of Spanish honey, the impact of industrial thermal treatment, and the effect of the year of collection. Citrus honey had the lowest levels of all the analysed variables, then rosemary and polyfloral, and honeydew the highest ones. Botanical origin affects the profile of flavonoids and phenolic compounds sufficiently to permit discrimination thanks to the predominance of particular compounds such as: hesperetin (in citrus honey); kaempferol, chrysin, pinocembrin, caffeic acid and naringenin (in rosemary honey) and myricetin, quercetin, galangin and particularly p-coumaric acid (in honeydew honey). The impact of industrial thermal treatments is lower than the expected variability as a consequence of the year of collection, though neither factor has enough influence to alter these constituent compounds to the point of affecting the discrimination of honey by botanical origin.

Risk assessment and critical control points from the production perspective

The implementation of a risk analysis program as risk assessment and critical control points (RACCP) is most necessary in order to accomplish the foodborne industries current objective of total quality. The novelty of this technique, when compared to actual hazard analysis and critical control points (HACCP) and its extension to incorporate elements of quantitative risk analysis (QRA), is that RACCP considers the risk of the consequences produced by the production process performance deviations, both inside and outside the company, and also identifies their causative factors. On the other hand, the techniques to be taken in order to prevent or mitigate the consequences of such deviations must be consistent with the former data, but the need for a cost-benefit assessment must not be ignored so that the chosen technique be most profitable for the company. An example developed in a mineral water bottling plant showed that RACCP application is feasible and useful. During this example case, RACCP demonstrated it could obtain a profitable production process that keeps quality and safety of the final product at its maximum, while providing protection to both company and consumer.

Changes in the volatile fraction during ripening of Mahón cheese

Abstract Mahon cheeses, manufactured in the Island of Minorca (Spain), were produced and ripened under controlled conditions. Cheeses were sampled and analyzed at different stages of ripening. Twenty-one major aroma components were identified. It was observed that, during ripening until the most commercially valuable product was obtained, (60–90 days) only 16 compounds varied significantly with time: butanoic, isovaleric, hexanoic, octanoic and decanoic fatty acids (p

Effect of chitosan–lemon essential oil coatings on volatile profile of strawberries during storage

Chitosan coatings containing lemon essential oils were described as effective at controlling fruit fungal decay at 20°C during 7 days. In this work, GC-MS was used to characterise the volatile compounds of strawberries during cold storage in order to analyse the influence of fruit coatings with chitosan, containing or not containing lemon essential oil, on the volatile profile of the fruits. The coatings affected the metabolic pathways and volatile profile of the fruits. Pure chitosan promoted the formation of esters and dimethyl furfural in very short time after coating, while coatings containing lemon essential oil incorporated terpenes (limonene, γ-terpinene, p-cymene and α-citral) to the fruit volatiles and enhanced the fermentative process, modifying the typical fruit aroma composition. No effect of chitosan coatings was sensorially perceived, the changes induced by lemon essential oil were notably appreciated.

Quality Characteristics, Respiration Rates, and Microbial Stability of Osmotically Treated Mango Tissue (Mangifera indica L.) with or without Calcium Lactate:

Mango minimally processed (20 °Brix) was obtained by applying osmotic treatments and the product quality development was evaluated throughout storage. Osmotic treatments were carried out at atmospheric pressure Osmotic dehydration (OD) and by applying a vacuum pulse osmotic dehydration (PVOD) using 45 °Brix sucrose solutions with and without calcium lactate (2%). Mechanical properties were measured after treatments and after 10 days storage. Color, microbial controls, and respiration rates were measured throughout storage time, in order to evaluate the development of the different parameters which affect product quality. Osmotic treatments induced changes in the physical properties, respiration rates and microbial behavior, depending on the treatment conditions and the addition of calcium lactate. From the microbiological point of view the most stable samples are those treated with calcium in both OD and PVOD treatments. Respiration rates were also reduced to a greater extent in these treatments. Mechanical properties are also better preserved when calcium is applied in PVOD treatments. Nevertheless, a greater decrease in hue is observed in calcium treated samples which indicates that browning occurs more intensely in these cases.

Effect of Honey Thermal Conditions on Hydroxymethylfurfural Content Prior to Pasteurization

Hydroxymethylfurfural (HMF) content is internationally recognized for its ability to indicate the freshness or lack of freshness of honey. Relevant standards stipulate that commercial honey intended for household consumption should have no more than 40 mg of HMF per kilogram of honey. This study investigated the correlation between changes in HMF content and changes in other quality criteria such as moisture content, conductivity, and total acidity when honey was subject to temperatures characteristic of the stages prior to industrial pasteurization. Furthermore, a model was created to predict increases in HMF content in the above stages. The study involved four different types of honey. Several thermal treatments were applied by combining different temperatures (between 35 °C and 65 °C) with periods of time ranging from 3 h to 28 days. Multivariate analysis showed no correlation between HMF content and the other three study variables. The application of a general linear model confirmed that the increases observed in HMF content were only correlated with time, temperature, and type of honey. The model created accounted for 75.47% of data variability and it is concluded that the predictive power of the model could be improved by modeling the storage temperature ranges apart from the liquefaction temperature ranges.

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.