Maria S. Tapia

Central University of Venezuela | UCV · Instituto de Ciencias y Tecnología de Alimentos (ICTA)

Water activity (aw) is a major factor in preventing or limiting microbial growth. In several cases, aw is the primary parameter responsible for food stability, modulating microbial response, and determining the type of microorganisms encountered in food. This chapter covers aspects that attempt to explain why the concept of aw has been successfully...

Today, and increasingly more often, humans tend to eat healthy diets that include an increase in the intake of fruits and vegetables as their beneficial effects on health have been evidenced. The produce industry is faced with an ever-increasing demand for fresh-likeness, convenience, and “health” in foods with the minimally processed fruit sector...

Passion fruit juice (PFJ) is very susceptible to thermal degradation and may benefit from processing by non-thermal methods such as sonication. This study pursued to test the effect of sonication on sensory quality and related chemical compounds of PFJ during refrigerated storage. Treatment conditions were those of a previous study where a microbio...

Passion fruit juice (PFJ) has a delicate flavour, very susceptible to thermal degradation. This study pursued to test the effect of sonication as non-thermal preservation method on some quality parameters of PFJ. The effect of ultrasound (20 kHz, 263 W, 89.25 μm) on the indigenous microflora, colour, pH, and ascorbic acid content of PFJ was studied...

One of the major growth segments in the food retail industry is minimally processed foods. This relatively new market trend has strived to develop new technologies or new applications of traditional technologies to preserve the characteristics of excellence in the products, extend shelf life, and improve their microbiological safety. Most of these...

Introducción: Este artículo recopila las prácticas de promoción del consumo de frutas y verduras por parte de ocho miembros de AIAM5 - Alianza Global de Promoción al Consumo de Frutas y Hortalizas “5 al día”, con el objetivo de identificar buenas prácticas en el planteamiento de estrategias, programas y actividades para la promoción del consumo de...

En la elaboración de películas antimicrobianas para recubrir alimentos, se agregan aceites esenciales, extractos de plantas y especias y aun cuando estas películas son efectivas contra agentes patógenos es importante realizar pruebas ante la posibilidad de que puedan producir cambios sensoriales en los alimentos

Macadamia nuts (Macadamia integrifolia) grown in Venezuela have showed an average total fat content of 70%. Oleic acid (18:1) was the main monounsaturated fatty acid (MUFA) (51.3%), followed by palmitoleic acid (16:1, 22.6%). The content of polyunsaturated fatty acids (PUFAs), C18:2 and C18:3 represented 5.4%. Thus, MUFAs and PUFAs together constit...

Films made from starches are colorless, tasteless, non-toxic, biodegradable, and economical, besides having a low permeability to oxygen. Moreover, the cross-linking modification (phosphatation) could improve its physicochemical properties by reinforcing the hydrogen links inside the granules. The goals of this study were to elaborate and character...

Several different hydrocolloids, such as starch, have been proposed as suitable base materials (matrices) for edible films in food packaging. Edible films from native and modified starch plasticized with glycerol were developed. Starches were obtained from dark cush-cush yam (Dioscorea trifida) and cassava (Manihot esculenta C.) from Venezuela, and...

Edible films based on 80:20 waxy:normal corn starch were evaluated for their potential use in the food industry. Two types of film were prepared by the casting method: The first from native corn starch and the second from starch modified with glycerol. The influence of this chemical modification on the physicochemical and mechanical properties of b...

Introduction. In recent decades, there has been increased interest in developing natural non-caloric sweeteners, providing sensory properties similar to sucrose. One of the most promising alternatives is the steviol glycosides, high-sweetness compounds extracted from the leaves of Stevia rebaudiana Bertoni. Characteristics and properties. In this r...

Fruit matrixes, like papaya (Carica papaya L. 'Maradol') may serve as a vehicle for micronutrients and bioactive components to obtain "functional fruits". In this work, a functional fresh-cut papaya product was elaborated by pulsed vacuum impregnation with isotonic solutions containing calcium, zinc, ascorbic and folic acid, bifidobacteria and olig...

Based on scientific evidence of the health benefits provided by fruits and vegetable (F&V), the food industry is very active introducing new products as alternatives for health-conscious consumers. This is quite pertinent in Latin America whose population follows diets high in carbohydrates and saturated fats, with low content of F&V. In this work,...

Cush-cush yam (Dioscorea trifida), is a sub-utilized tropical crop, rich in starch, which grown in tropical areas. The exploitation of its starch has great potential. The objectives of this research was to modify starch isolated from dark-cush-cush yam, which grown in the Venezuelan Amazonian, and commercial cassava starch, by cross linking, in ord...

A small number of sweetening compounds, low in calories and with sensory profiles similar to sucrose, are commercially used in various food products. Among them, it is notorious the interest that in the last decade have generated natural sweeteners, particularly glycoside obtained from leaves of Stevia rebaudiana because of its high sweetness and s...

Starches can be used to form edible or biodegradable films, and recently modified starches have been used to form self-supporting films by casting from aqueous solution. In this work, we aimed to propose a novel starch-based composite biomaterial matrix for use in biomedical applications, especially tissue engineering. The goal of the study was to...

This work aimed to characterize the molecular structure and functional properties of starches isolated from wild Dioscorea yams grown at the Amazons, using conventional and up-to-date methodologies. Among the high purity starches isolated (≥99%), the chain lengths were similar, whereas variations in gelatinization profile were observed. Starches ha...

In recent years, the consumption of fresh-cut fruit has been associated with outbreaks of diseases caused by different emerging pathogenic microorganisms. Therefore, great efforts to find methods that ensure the quality and safety of minimally processed products are needed. The main objective of this study was to evaluate the effect of different do...

El objetivo de este estudio fue evaluar las propiedades mecánicas (solubilidad, extensibilidad y ruptura), de barreras (permeabilidad al vapor de agua (PVA), oxígeno y dióxido de carbono) y antimicrobianas (contra Staphylococcus aureus, Listeria monocytogenes y Salmonella Enteritidis) de las películas comestibles de alginato de sodio (2% p/v) y de...

Biopolymers from agricultural starchy commodities can be raw materials for edible, biologically degradable plastics. They have promising uses, having been proposed for replacing synthetic films. There are several starchy sources not yet quite exploited such as tropical roots and tubers that could be excellent starch sources to produce edible films...

Native and modified starches from non-conventional sources could be used as raw materials that represent appropriate bio-matrices to support diverse bioactive sub-stances when formulating composite edible films or foams. In order to be used as raw materials, the starch and the starch-based films or foams obtained have to be characterized. The goals...

The effect of temperature (10–30 °C), relative humidity (RH, 50–90%), and storage period (2–10 days) were studied on the production and sustainability of thiocyanate (SCN−) and hypothiocyanite–hypoiodite (OSCN−, OI−) components of a lactoperoxidase system (LPOSI) in chitosan film by applying response surface methodology and Doelhert experimental de...

La Biotecnología alimentaria aprovecha el desarrollo de la microbiología y la biología molecular para innovar en la producción de alimentos de calidad más sanos y seguros, así como en el desarrollo de procesos industriales de producción y control. En Venezuela son escasas las empresas del sector alimentario que emplean la biotecnología y las herram...

La identificación de microorganismos probióticos del género Bifidobacterium es de gran importancia por su uso como suplemento que favorece la salud del consumidor. En Venezuela son pocos los estudios sobre caracterización microbiológica de estas bacterias y no existen métodos oficiales para su estudio en alimentos. Esta investigación reporta la est...

Se estudió el efecto de diferentes dosis de luz UV-C y ácido málico sobre Rhodotorula glutinis (flora deteriorativa predominante) en trozos de papaya variedad “Maradol” inoculadas. Papayas frescas cortadas fueron sumergidas en soluciones conteniendo ácido málico (0, 0.5, 1.0 y 1.5%), lactato de calcio (1%) y ácido ascórbico (0,5%) por 1 min, luego...

The incorporation within the preventive control programs used for managing safety in the whole produce and fresh-cut produce industry, of a hurdle approach that utilizes individual sublethal stressors (physical, chemical, and biological methods), in a sequential application with a cumulative inhibitory effect on the microbiological load present in...

La identificación de microorganismos probióticos del género Bifidobacterium es de gran importancia por su uso como suplemento que favorece la salud del consumidor. En Venezuela son pocos los estudios dirigidos a la caracterización microbiológica de estas bacterias y no existen métodos oficiales para su estudio en alimentos. Esta investigación repor...

Freshness attributes in food products continue to be a trend of relevance to consumers. UV-C light treatment of fluid foods is a non-thermal process potentially suitable to obtain high-quality fruit nectars. This study pursued to test the effect of UV-C light treatment on indigenous microorganisms and sensory quality of two tropical fruit nectars....

The effect of different doses of UV-C light and malic acid on Rhodotorula glutinis (predominant spoilage flora) inoculated on pieces of 'Maradol' papaya was studied. Fresh-cut papayas were dipped into solutions containing malic acid (0, 0.5, 1.0, and 1.5%), calcium lactate (1%) and ascorbic acid (0.5%) by 1 min. Afterward, the samples were inoculat...

Purpose of review: This article reviews the incorporation of food additives into edible coatings for preserving and extending the shelf-life of fresh-cut fruits and vegetables. Findings: During minimal processing operations such as peeling, cutting, shredding, coring, etc, the integrity of fruit and vegetable tissues is altered. Cell wall breakdown...

Ultrasonic treatments were applied at a frequency of 20 kHz and three wave amplitudes for 2, 4, 6, 8 and 10 min, to orange juice with added calcium. Aerobic mesophilic count (AMC), yeast and mold counts (YMC), Hunter color values, ascorbic acid concentration and sensory attributes were measured. Wave amplitude of 89.25 μm for 8 min was selected for...

There is a growing epidemic of chronic non-communicable diseases (NCD) related to changes in eating habits and unhealthy lifestyles. Chronic diseases are also among the leading causes of mortality in Venezuela. The “5aday” initiative is being promoted in the country since year 2006 by the Universidad Central de Venezuela (UCV). The UCV has been try...

Arepa is an important part of the Venezuelan and Colombian diet. The introduction in the market of a ready-to-cook-arepa of long lasting life on the market shelves at room temperature, or refrigeration, will be a great convenience. Studies were conducted to determine the sensory shelf-life of a ready-to-cook-arepadevelopd in the laboratory. Microbi...

Purpose of the review: This review focuses on the complex task of the final implementation of HACCP by fresh-cut processors. In the face of recent episodes involving safety of produce and fresh-cut products, HACCP has been highly demanded for this industry by regulators, politicians, consumers and the market. Findings: The incidence of illnesses ca...

The use of alginate- (2% w/v) or gellan-based (0.5% w/v) coating formulations on fresh-cut papaya pieces was investigated in order to determine their ability to improve water vapor resistance (WVR), to affect gas exchange and to carry agents that help to maintain the overall quality of the minimally processed fruit. Formulations containing 2% (w/v)...

W ater Activity in Foods: Fundamentals and Applications is a one-of-a-kind reference text that brings together an international group of food scientists, chemists, and engineers to present a broad but thorough coverage of an important factor known to influence the attributes of foods – water activity (a w). A team of experienced editors designed th...

The effect of alginate and gellan-based edible coatings on the shelf-life of fresh-cut Fuji apples packed in trays with a plastic film of a known permeability to oxygen (110 cm3 O2 m−2 bar−1 day−1) was investigated by measuring changes in headspace atmosphere, color, firmness and microbial growth during 23 days of storage at 4 °C. Concentration of...

Alginate- (2% w/v) or gellan-based (0.5%) edible films, containing glycerol (0.6% to 2.0%), N-acetylcysteine (1%), and/or ascorbic acid (1%) and citric acid (1%), were formulated and used to coat fresh-cut apple and papaya cylinders. Water vapor permeability (WVP) was significantly higher (P < 0.05) in alginate films (0.30 to 0.31 x 10(-9) g m/Pa s...

La leche de coco es una emulsión obtenida de la extracción acuosa del endospermo del fruto o carne, tiene un sabor agradable y puede ser una fuente calórica importante, además de que por su composición en ácidos grasos podría considerarse como un alimento funcional. Esta revisión contempla datos composicionales (fisicoquímicos y nutrimentales), así...

Alginate (2% w/v) and gellan (0.5% w/v)-based edible coatings were formulated to study the effect of glycerol (G) and antibrowning agents (N-acetylcysteine and glutathione) on water vapor resistance (WVR). The ability of the coatings to carry antibrowning agents was investigated following color changes of coated fresh-cut Fuji apples. Selected form...

La inocuidad de los alimentos es un aspecto fundamental de salud pública y elemento esencial para la gestión de la calidad total, por lo cual es tema de alta prioridad para todos los países y gobiernos. En Venezuela este tema requiere la mayor atención debido a las implicaciones para la salud que alcanzan a todos los estratos de la población; a las...

Según la OMS/FAO el bajo consumo de frutas y verduras (F&V) es uno de los factores de riesgo de las enfermedades crónicas no transmisibles (ENT), representando las principales causas de mortalidad en Venezuela. Las F&V han estado ausentes de los programas y políticas de salud pública para prevención primaria de ENT, si bien las guías alimentarias r...

According to WHO/FAO, low fruit and vegetables (F&V) intake is one of the main risks factors of non communicable diseases (NCD) accounting for the high mortality rates occurring in Venezuela. F&V have been absent from Venezuelan official health programs and policies for prevention of NCD, as well as from programs aiming to increase food supply, eve...

Fresh persimmons were subjected to two different processes: sun-drying during 1 month and dehydration at 60 °C during 12 h. To assess the effect of this process on nutritional and health-related properties of persimmons dietary fibers, minerals, trace elements, polyphenols and the total radical scavenging activities (TRSAs) were determined before a...

ABSTRACTA water activity (aw) model for multicomponent systems expressed as a linear first order sum of molalities and requiring only data from binary solutions was tested. The model was developed based on a linear relationship between aw and molality for each solute. Water activity predictions were validated and compared with Ross’equation using a...

ABSTRACT Response surface methodology was used to study the effect of antibrowning agents (4-hexylresorci-nol, glutathione, N-acetylcysteine, and ascorbic acid) and storage time (14 d) on the color of minimally processed Fuji apples. The selected color parameters were L*,a*, b*, hue angle (h*), and color difference (ΔE*). Storage time had a signifi...

The teaching of food engineering (FE) in Mexico and Central and South America began more than 50 years ago, initially with programs related to Chemical Engineering and Chemistry. The first programs clearly denominated as FE emerged during late 1960s and early 1970s; the support of the Organization of American States (OAS) and United Nations (UN) in...

Bioactive compounds of peels and peeled red Star Ruby (Sunrise) and blond qualities of Jaffa grapefruits were analyzed and their antioxidant potential was assessed. The dietary fibers were determined according to Prosky et al., the total polyphenol content by Folin-Ciocalteu method and measured at 765 nm, minerals and trace elements by atomic absor...

Functional foods affect beneficially one or more target functions in the body, beyond adequate nutritional effects, to either improve stage of health and well-being and/or reduce the risk of disease. Lastly, the range of functional foods has grown tremendously. One of the main objectives of the multinational collaborative project entitled “Emerging...

A surface response analysis was carried out using the Box-Behnken method in order to determine the effects and interactions of pH (4.5, 5.5, 6.5), temperature (2, 7, 12 °C) and Capsicum extract concentration (0%, 5%, 10%) on the growth kinetics of Listeria monocytogenes Scott A in trypticase soy broth. Survival ratio quadratic models (log N/N0) wer...

Organizations that are very large or ones with complicated processes do not function well without first implementing management systems (MS), although they may be called by some other name. Food companies are no exception, and have been operating management systems of their own for many years. One type of MS is provided by the International Organiz...

Se desarrolló un diseño central compuesto para optimizar la aceptación global en la formulación de un néctar de mora, considerando como variables las cantidades de agua y sacarosa incorporadas a la mezcla. Mediante el modelo matemático ajustado a partir del diseño experimental, se obtuvo por derivadas parciales el óptimo matemático de la función y...

A simple model based on mass balance equations is proposed for prediction of the final mass and composition of products subjected to vacuum impregnation. It was applied to some tropical fruits in a fruit-sucrose solution system. The phenomenon can be described in terms of volumetric fraction of impregnating solution as the basic modeling parameter,...

In order to design a minimal process for cantaloupe, the water activity of the fruit was reduced until 0.976 through vacuum osmotic dehydration and the optimum combination of microbial preservatives (100 ppm sodium sulfite, 600 ppm potassium sorbate, 0.5% L-ascorbic acid and 1% citric acid), that contributed to minimize (p < 0.05), the content of a...

In order to design a minimal process for cantaloupe, the water activity of the fruit was reduced until 0,976 through vacuum osmotic dehydration and the optimum combination of microbial preservatives (100 ppm sodium sulfite, 600 ppm potassium sorbate, 0,5% L-ascorbic acid and 1% citric acid), that contributed to minimize (p<0,05), the content of aer...

The application feasibility of an artificial neural network model to predict the characteristic nonlinear behavior of moisture adsorption isoterms in foods was evaluated. Seven products were selected: corn germ flour, wheat flour, polished rice flour, unpolished rice flour, soybean flour, sweet potato flour and powdered milk. For each product, mois...

Fruits have always been of interest to food scientists as raw materials for processed products due to their high value and wide appeal to consumers. However, traditional processed fruit products (canned, frozen, dried, etc.) are still an important part of our food supply, and numerous other minor or specialty fruit products are needed to meet a spe...

Minimally processed foods and partially processed foods (fresh–like foods) began to appear on the market at the industrial level in the late 1980s and early 1990s as an answer to the needs of consumers who were interested in products that were fresh, as well as easy to prepare and serve (Resurrection and Prussia, 1986; Mertens and Knorr, 1992). The...

The application of vacuum osmotic impregnation at constant temperature (25 °C) to obtain high moisture minimally processed papaya was evaluated. The fruit effective porosity was determined employing vacuum impregnation in isotonic sucrose solutions, obtaining values of around 3.4%. The fruit was submitted to vacuum osmotic dehydration (VOD) process...

The application of vacuum osmotic impregnation at constant temperature (25°C) to obtain high moisture minimally processed papaya was evaluated. The fruit effective porosity was determined employing vacuum impregnation in isotonic sucrose solutions, obtaining values of around 3.4%. The fruit was submitted to vacuum osmotic dehydration (VOD) processe...

Minimally processed foods represent a problem from the point of view of microbiological safety, since their processing implies a loss of extrinsic and intrinsic preservation factors. This paper analyzes the microbiological status of minimally processed foods and the prospects to extend their microbiological safety by the hurdles technology. Some is...

Innovative technologies for producing minimally processed (MP) foods that apply the concept of combination of preservation factors are addressed in this article with special emphasis on a new combined approach that has been successfully applied in several Latin American countries for MP high-moisture fruit products (HMFP). HMFP can be regarded as a...

This paper presents the processes developed for preserving ‘high moisture fruit products’ (peach, pineapple, mango, papaya, chicozapote, banana) in seven countries in the frame of CYTED-D Program. The new technologies were based on the combination of a mild heat treatment, a slight water activity (aw) reduction, and addition of antimicrobials (‘hur...

Las frutas en general son buenos ejemplos de alimentos con microestructura porosa, la cual puede ser usada en el desarrollo de nuevos productos, utilizando impregnación a vacío y a presión atmosférica para incorporar compuestos bioactivos, por el mecanismo hidrodinámico. En este estudio, se determinó la porosidad efectiva del melón (Cucumis melo L....