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Tecnología y Procesamiento de Alimentos

Reducción de pérdida de calidad de melón (Cucumis melo) durante la congelación mediante aplicación previa de deshidratación osmótica


El propósito de este trabajo fue evaluar el efecto de un pre-tratamiento osmótico con dos niveles de humedad (85 y 75%) y el tiempo de almacenamiento sobre la pérdida de fase líquida (∆m), cambio de volumen (∆V) y luminosidad (L*) de cilindros de melón congelados (2 cm de diámetro y 1.5 cm de altura). Las muestras previas a la congelación se deshidrataron en una solución osmótica (SO) de sacarosa comercial a 65 °Brix a 28 °C. La SO se agitó permanentemente a 440 rpm mediante un agitador mecánico con una relación fruta-solución de 1-20. Las muestras frescas (control) y las osmodeshidratadas se congelaron a -40 °C en un ultra-congelador, posteriormente se empacaron en bolsas de congelación y se almacenaron en un congelador a -18 °C durante 15 días. La ∆m se determinó por diferencia de peso empleando una balanza analítica, el volumen se midió con un calibrador digital y L* se midió con un colorímetro. El ANOVA evidenció efectos significativos (p<0.05) del pre-tratamiento osmótico y del tiempo de almacenamiento sobre ∆m, ∆V y L*. Las muestras deshidratadas osmóticamente hasta niveles de humedad de 85 y 75% presentaron menores pérdidas de ∆m con respecto a la muestra control, alcanzando en el día 15 valores de 24.42, 33.35 y 38.8% respectivamente. Asimismo, los tratamientos 85 y 75% presentaron menores pérdidas de volumen con 29.96 y 31.64% respectivamente, mientras que el control perdió el 41.25%. Las muestras frescas presentaron valores superiores de L* (41) con respecto a los tratamientos 85% (35.88) y 75% (45), pero estas diferencias no son relevantes en la calidad del melón. La aplicación de pre-tratamientos osmóticos a la congelación de melón evidenció un efecto crioprotector (reducción de pérdidas de calidad); esta aplicación de pre-tratamientos osmóticos ofrece un alto potencial para la reducción de pérdidas de calidad a otras frutas durante la congelación.

Alejandra Bermúdez
Maritza Narváez
Martha I. Cadena
Alfredo Ayala Aponte
Revista Alimentos Hoy
2,013
Effect of process parameters on the effectiveness of osmotic dehydration of summer onion


The present study was carried out to investigate the effects of solution concentration, immersion time and temperature on the osmotic dehydration (OD) of summer onion. OD was done using sucrose, salt and combined (sucrose-salt) solution. In this study three sucrose (40,50 and 60%), five salt (5,10,15,20 and 25%) and five sucrose- salt (combine) solution (40:15, 45:15, 45:20 50:15 and 55:15 %) were used. Among different solution concentration and temperature for 6 hrs contact time 55:15°brix at 40°C gave water loss (50.05%), solid gain (16.25%) and normalized solid content (2.34), while 60 °brix sucrose solution gave 35.60%, 9.32%, 1.81 and 25°brix salt solution gave 33.50%, 12.21%, 2.25 water loss, solid gain and normalized solid content respectively. It was also found that at ambient temperature (25°C) 55:15°brix for 24 hrs contact time gave the highest water loss (56%) and solid gain (17.80%). It can be concluded from this study that solution temperature, time and concentration were the most pronounced factors affecting solid gain, water loss and normalized solid content of onion slice during osmotic dehydration.

M.M. Alam
M. N. Islam
M.N. Islam
International Food Research Journal
2,013
Concentrated solar drying of tomatoes

 
Fruits and vegetables are an integral part of the human diet. Many developing countries such as Tanzania experience post-harvest losses of 40%, and there is little ability to preserve and store foods for off-season consumption due to expensive or unreliable energy and a lack of access to refrigeration. Alternatively, fruits and vegetables can be dehydrated using solar crop dryers. Because many developing countries are in tropical regions, properly dehydrating fruits and vegetables to moisture levels appropriate for storage and off-season consumption can be difficult. In an attempt to overcome the challenges of the high humidity, intermittent clouds, and haze often present in tropical climates, this paper investigates the effectiveness of adding a concave solar concentrator built from low-cost, locally available materials to a typical Tanzanian solar crop dryer. Two identical solar crop dryers were constructed, with one serving as the control and the other for testing the solar concentrator. Drying trials using Roma tomatoes with initial moisture content of approximately 90% were conducted in Davis, California (38° 32′ 42″ N/121° 44′ 21″ W) in various climatic conditions throughout the summer and fall. Tomatoes were considered dried at 10% moisture content. Temperature, relative humidity, and solar radiation were measured outside as well as within each of the dryers to determine how the addition of a solar concentrator can affect the drying rate of tomatoes in solar crop dryers. The concentrator proved to be effective, reducing drying time by 21% in addition to increasing internal dryer temperature and reducing relative humidity. An additional study on the quality of the fresh and dried tomatoes found that the pH, titratable acidity, color, Brix, lycopene, and vitamin C determined there was no significant difference in quality between tomatoes dried with and without the concentrator.

Blake Ringeisen
Diane M. Barrett
Pieter Stroeve
Energy for Sustainable Development
2,014
Effect of Pre-drying, Blanching and Citric Acid Treatments on the Quality of Fried Sweet Potato Chips

 

Frying of sweet potato slices is carried out to convert the roots to value added products. Frying method brings out unique flavor and texture to the products that improve their overall acceptability. The aim of this work was to determine the effect of some pretreatments on moisture, vitamin C content and color and oil absorption of fried sweet potato chips. Prior frying, sweet potato slices were pre-dried and blanched and pre-dried or treated with 0.1% citric acid solution and pre-dried. The pre-drying treatments were carried out at 70°C for 0, 30, 50 and 70 min. The mean of moisture content of the dried, blanched and citric acid treated chips were in the range of 1.38-1.91, 1.04-1.41 and 1.35-1.88%, respectively. While, the fat content in the same samples ranged between 12.57-14.23, 14.09-17.92 and 12.31-14.54%, respectively. Vitamin C content in fried sweet potato chips pre-dried only, blanched and pre-dried and citric acid treated and pre-dried ranged between 17.43-40.50, 9.23-29.23 and 19.87-44.93 mg 100 g-1, respectively. The samples pre-dried only gave darker chips compared to that blanched and pre-dried or citric acid treated and pre-dried. Fried sweet potato chips treated with citric acid and pre-dried for 50 min had the best sensory scores for all sensory quality attributes.

G. Abdulla
Gehan A. El-Shourbagy
Mahmoud Z. Sitohy
American Journal of Food Technology
2,014
Agro-industrial utilization of cactus pear


Cactus pear (Opuntia spp.) makes a valuable contribution to the food security and nutrition of people throughout the world wherever water is scarce. The plant is highly versatile and, in addition to feeding people, it is widely used for livestock feed, burned as fuel and used to protect the environment in which it is grown. Opuntia spp. provides the basis for viable rural communities.
There are more than 300 species of the Opuntia genus, which originated in Mesoamerica and subsequently spread throughout the world, adapting to different agro-ecological zones and to the demands of people, to preferences for traditional foods and culinary tastes, and to the constraints imposed by different agricultural practices.
The versatility of Opuntia spp. makes it particularly useful to small-scale producers and provides the basis for exploiting the species in applications ranging from home-grown produce prepared in the home, to small-scale and large-scale production/processing value chains. Agro-industrial manufacturing enables cactus products to be packaged and shipped over long distances, stored safely and sold in supermarkets wherever there is a demand for these foods. For smallholders, production of the resilient cactus species provides opportunities for wealth creation and improved living conditions for rural communities.
This publication (originally published in Spanish in 2006) confirms the importance of cactus production and explores the opportunities forboosting productivity throughout the value chain from farm to consumer. The ten chapters cover the biological, technical, socio-economic and industrial potential of this relatively well-known, but sometimes little appreciated crop.
This easy-to-follow guide is based on research and development work by institutions, mainly in Latin America, and the practicalities of artisanal and commercial agro-industries linking producers with consumers. It describes harvesting through to post-harvest handling, storage and delivery to the processing plant, as well as the equipment and technologies required for different scales of production. It also highlights the extraordinary resilience and value of Opuntia spp. and the contribution it can make to agro-economies and agro-environments wherever it can be grown.

Carmen Sáenz
Horst Berger
Armida Rodríguez-Félix
Ljubica Galletti
Joel Corrales García
Elena Sepúlveda
María Teresa Varnero
Víctor García de Cortázar
Roberto Cuevas García
Enrique Arias
Candelario Mondragón
Inocencio Higuera
Cadmo Rosell
FAO
2,013
Studies on Debittering of Sweet Orange Juice

 
Sweet orange is the important citrus fruit crop grown throughout the world; it contributes 71 per cent of the total citrus fruit production. Fresh juice of sweet orange is refreshing, thirst quenching and energizing drink that improves health and nutritional requirements. It provides 45 kcal, moderate quantity of vitamin C, potassium, bioflavonoids and folic acid. Cost of processing and development of bitterness in sweet orange juice shortly after extraction is the factor for low consumption of sweet orange juices. This bitterness is caused mainly by a compound limonin in sweet orange juice. The bitterness caused by limonin is referred as delayed bitterness since it is not detected in fresh juice but develops gradually and slowly during storage or with heat treatment. Hence an attempt is taken to develop an economic process to reduce the bitter component limonin from sweet orange juice.

A.N. Siddiqui
D.N. Kulkarni
K.D. Kulkarni
M.Z. Mulla
World Journal of Dairy & Food Sciences
2,013
Optimización de las condiciones de deshidratación osmótica de espárrago (Asparragus officinalis) utilizando la metodología de superficie de respuesta

Se realizó un Screening utilizando un diseño factorial fraccionado, las variables independientes fueron la concentración de NaCl (4 – 20%), temperatura (20 – 50°C), tiempo de inmersión (10 – 300 min), velocidad de agitación (0 – 150 rpm) y una relación solución/producto  (10/1 – 30/1) y como variables dependientes la humedad final y la ganancia de sólidos. Las variables significativas (p<0.05) fueron la concentración de NaCl, la temperatura y el tiempo de inmersión. Luego se utilizó un Diseño Central Compuesto Rotacional (DCCR) para la segunda etapa de optimización. Los modelos obtenidos para la humedad final y ganancia de sólidos fueron validados a través del Análisis de Regresión y ANVA (significativo en ambos casos). Se determinó los valores óptimos (T° = 36 - 42°C, concentración = 30 - 32% y tiempo de inmersión = 350 a 370 min) que minimizan el contenido de humedad final y maximizan la ganancia de sólidos. Finalmente a condiciones óptimas fueron obtenidos los valores de difusividad efectiva media de 7.89342x10-10 m2/s para el agua y 6.34758x10-10  m2/s para la Ganancia de Sólidos.

David Torres Celis
Daniel Salvador Rodríguez
Roger Baltazar Flores
Raúl Siche
Agroindustrial Science, Universidad Nacional de Trujillo, Perú
2,013
Development of frozen-fried yam slices: optimization of the processing conditions


The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was to optimize frying conditions of deep-frozen fried yam (Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by pre-frying temperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yam slices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yam tuber.

Y Touré
C Nindjin
Y Brostaux
GN Amani
M Sindic
African Journal of Food, Agriculture, Nutrition and Development
2,012
Mechanical Strategies to Increase Nutritional and Sensory Quality of Virgin Olive Oil by Modulating the Endogenous Enzyme Activities


This monograph is a critical review of the biological activities that occur during virgin olive oil (VOO) extraction process. Strategic choices of plant engineering systems and of processing technologies should be made to condition the enzymatic activities, in order to modulate the nutritional and the sensory quality of the product toward the consumer expectations. “Modulation” of the product quality properties has the main aim to predetermine the quantity and the quality of 2 classes of substances: polyphenols and volatile compounds responsible of VOO nutritional and sensory characteristics. In the 1st section, a systematic analysis of the literature has been carried out to investigate the main olive enzymatic activities involved in the complex biotransformation that occurs during the mechanical extraction process. In the 2nd section, a critical and interpretative discussion of the influence of each step of the extraction process on the polyphenols and the volatile compounds has been performed. The effect of the different mechanical devices that are part of the extraction process is analyzed and recommendations, strategies, and possible avenues for future researches are suggested.
Practical Application
In the field of virgin olive oil industry, time and energy should be spent on developing innovative processing plants and equipment able to better modulate the physical parameters that influence endogenous olive enzyme activities, such as temperature, time, amounts of processing water and oxygen. This review paper can be a useful resource to design and develop innovative equipment by offering an exhaustive analysis of mechanical effects of industrial devices and biological effects of endogenous enzymes on the sensory and nutritional properties of virgin olive oil.

Maria Lisa Clodoveo
Rim Hachicha Hbaieb
Faten Kotti
Giacomo Scarascia Mugnozza
Mohamed Gargouri
Comprehensive Reviews in Food Science and Food Safety
2,014
Desarrollo y caracterización de un producto libre de gluten a base de harinas de maíz, arroz y quinua


Se desarrolló un producto (galletas) libre de gluten a base de una harina compuesta de maíz, arroz y quinua. Se obtuvieron las harinas de maíz y quinua por molienda y se adicionó harina de arroz comercial. Se determinó la granulometría de las harinas y se hicieron ocho formulaciones de mezclas a partir del diseño factorial empleado, dando 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 65:35 y 60:40 (maíz: arroz + quinua, estas últimas en partes iguales). Se evaluaron los índices de absorción y de solubilidad en agua y las mezclas 60:40 y 70:30 presentaron las mejores características (baja absorción y alta solubilidad). El análisis proximal de las harinas, reveló una composición acorde con los reportes de la literatura. Se obtuvieron micrografías SEM de las harinas y se estudiaron algunas propiedades reológicas de las harinas y de sus mezclas (consistencia, curva de empastamiento y viscosidad), encontrando que las mezclas formaban geles estables. Se produjeron masas de todas las mezclas y se evaluó su compresión uniaxial como propiedad textural. A las galletas obtenidas de las ocho mezclas, se les evaluó la humedad, cumpliendo con la Norma Técnica Colombiana NTC 1241; también, se determinó su dureza con un texturómetro. Finalmente, se hizo un análisis sensorial con un panel hedónico semientrenado con escala de cinco puntos, resultando que la formulación de galletas de mayor aceptación correspondió a la mezcla 70:30, cuya dureza fue 23,5 N y su compresión de 41,4 N. El producto obtenido cumplió con los requerimientos de formulación, de composición, de procesabilidad y de aceptación sensorial. Estos resultados indican que se pueden desarrollar productos funcionales de panificación (basados en quinua) con propiedades que favorezcan poblaciones con problemas nutricionales específicos, en este caso, aquellos con enfermedad celíaca.

Karen Ortega Guerrero
Diana Carolina Hernández Duque
Harold Acosta Zuleta
Revista Alimentos Hoy
2,013
Design Development of a Unit Operation for Chilli Paste Process

 
The traditional method of chilli paste processes essentially consists of two main unit operations, namely blending of raw ingredients and cooking of liquefied chilli paste, accompanied by manual stirring. The transferring of blended food for cooking adds clean-up work and tends to waste time and energy. Substantive continuous stirring during the cooking process is essential, but time and labour consuming. In this study, a process design of a chilli paste machine has been developed with the aim to combine the process of blending and agitated cooking in a single appliance. A new design of machine called Chilli Paste Machine has been successfully built with the intention to overcome the issues present in making chilli paste. It comprises a set of blades that enable blending or stirring of chilli paste during blending and cooking processes respectively. A heating plate is installed for heating the chilli paste. The whole operation is controlled by a Programmable-Logic-Controller (PLC) Unit which allows automated control of the desired temperature parameters. The prototype machine was tested to ensure the performances of the machine design are met. A ready-to-serve batch of chilli paste was successfully produced using this newly designed machine.

M.K. Siti Mazlina
L. Sze Ying
M.S. Intan Shaidatul Shima
I. Iryane
American Journal of Food Technology
2,014
Preserving Food Jams and Jellies

 
Sweet spreads–butters, jellies, jams, conserves, marmalades and preserves–add zest to meals. They can be made from fruit that is not completely suitable for canning or freezing. All contain the four essential ingredients needed to make a jellied fruit product–fruit, pectin, acid and sugar. They differ, however, depending upon fruit used, proportion of different ingredients, method of preparation and density of the fruit pulp. Jelly is made from fruit juice and the end product is clear and firm enough to hold its shape when removed from the container. Jam is made from crushed or ground fruit. The end product is less firm than jelly, but still holds its shape. This circular deals with the basics of making jellies and jams, without adding pectin. Recipes for making different spreads can be found in other food preservation cookbooks. Recipes for using added pectin can be found on the pectin package insert sheets.
Essential Ingredients
Fruit furnishes the flavor and part of the needed pectin and acid. Some irregular and imperfect fruit can be used. Do not use spoiled, moldy or stale fruit. Pectin is the actual gelling substance. The amount of pectin found naturally in fruits depends upon the kind of fruit and degree of ripeness. Underripe fruits have more pectin; as fruit ripens, the pectin changes to a non-gelling form. Usually using 1⁄4 underripe fruit to 3⁄4 fully-ripe fruit makes the best product. Cooking brings out the pectin, but cooking too long destroys it. High pectin fruits are apples, crabapples, quinces, red currants, gooseberries, Eastern Concord grapes, plums and cranberries. Fruits lower in natural pectin include blueberries, peaches, apricots, pears, raspberries, blackberries and figs. These low-pectin fruits should be combined with one of the high-pectin fruits or with a commercial pectin. When a commercial pectin is added, fully ripe fruit can be used. The use of this added pectin also increases the yield from a recipe. Jams and jellies may be made from low pectin fruits using the recipes in this publication that do not call for adding commercial pectin, but they may not gel properly every time. Commercial pectins come in liquid and powdered forms. Both give satisfactory results, but the amounts of ingredients per package and the methods of adding recipe ingredients differ. For this reason, the powdered and liquid forms are not interchangeable. Be sure to follow the manufacturer’s recipes and instructions. Store pectins in a cool, dry place and use before expiration dates on the packages. Pectin found naturally in fruits or in regular commercial pectins will not gel without a certain amount of sugar. To make gelled spreads without added sugar or with reduced sugar, modified pectins must be used. Currently there are special pectins available to make jellies and jams with either no added sugar or with 1/3 less sugar than regular recipes. Follow the recipes provided by the manufacturer with each type of pectin. The sugar is required in the recipes in this publication.

Judy A. Harrison, Ph.D.
Elizabeth L. Andress, Ph.D.
The University of Georgia
2,013
Vanilla Post-harvest Operations


Vanilla (Vanilla planifolia A.) is a major natural flavor widely used in many industries as food, beverages, sodas, pharmaceutics, cosmetics tobacco and traditional crafts. Vanilla beans originated in Mexico, and in some Central American countries as Costa Rica and Honduras. However, today vanilla beans are cultivated in many areas of the world and the main producing countries are Madagascar, Indonesia, China, Comores and in a lesser extent Tonga, Reunion, Turkey and Guadeloupe. In México, the main producing area is located in the Totonacapan, located in the northern part of the state of Veracruz. In recent years the Mexican states of Oaxaca and Puebla have joined Veracruz for production and processing of vanilla beans (Musalem, 2002).
Contents
1. Introduction
   1.1 Economic and social impact of the vanilla crop
   1.2 World trade
   1.3 Primary product
   1.4 Alternative products from vanilla
   1.5 Requirements for export and quality assurance
   1.7 Varieties and commercial cultivars
2. Harvesting and Post-production operations
   2.1 Harvesting
   2.2 Yield
   2.3 Packing
   2.4 Packinghouse operations
   2.5 Pre-treatments
3. Pest species and pest control and decay

Javier De La Cruz Medina
Guadalupe C. Rodriguez Jiménes
Hugo S. García
Thelma Lucía Rosado Zarrabal
Miguel Ángel García Alvarado
Víctor José Robles Olvera
FAO
2,009
Organic Cultivation of Mangoes

 
The mango grows best in tropical summer rain regions, at temperatures between 24°C and 28°C. Despite being fully foliated, the trees are remarkably resistant against drying out. A dry period or cooler temperatures enliven the blossoming and the production of mangoes. A period of respite in the growth of vegetation is necessary to enable blossoming. The trees will therefore not produce any fruits in those moist tropical regions that lack a definite seasonal rainfall or temperature fluctuations. Mango trees can also thrive in the sub-tropics (Egypt, Israel). Some varieties can even withstand a light frost. Young seedlings must nevertheless be protected from damage through frost (e.g. with straw or palm leaves). Mangoes have few soil requirements. A healthy, high yielding plantation is nevertheless only possible on fertile, deep and well-drained ground.
Contents:

  • Introduction
    • Botany
    • Varieties and countries of origin
    • Uses and contents
  • Aspects of plant cultivation
    • Site requirements
    • Seeds and seedlings
      • Propagation
      • Flower formation
    • Planting methods
    • Diversification strategies
    • Nutrients and organic fertilisation management
      • Nutrient requirements
    • Biological methods of plant protection
      • Diseases
      • Pests
    • Crop cultivation and maintenance
      • Young plants
      • Crop monitoring
    • Harvesting and post-harvest treatment
      • Harvesting
      • Post harvest treatment
  • Product Specifications and Quality Standards
    • Fresh mangoes
      • Preparation
      • Packaging and storage
    • Dried mangoes
      • Processing
      • Quality requirements
      • Packaging and storage
    • Mango marmalades
      • Processing
      • Quality requirements
      • Packaging and storage
    • Canned mangoes
      • Processing
      • Quality requirements
      • Packaging and storage
    • Mango pulp
      • Processing
      • Quality requirements
      • Packaging and storage
Franz Augstburger
Jörn Berger
Udo Censkowsky
Petra Heid
Joachim Milz
Christine Streit.
Naturland e.V.
2,001
Manual para la Elaboración de Productos Derivados de Frutas y Hortalizas

 
Dado que las frutas y hortalizas son productos altamente perecederos, los esfuerzos realizados para elevar la producción se desvanecen, pues ocurren grandes pérdidas en las etapas posteriores a la cosecha. Ante esta situación, es necesario capacitar a los productores en el procesamiento de frutas y hortalizas, técnica que les permitirá otorgar valor agregado a su producto y diversificar sus ingresos. Con el fin de combatir esta problemática, se ha generado el presente manual, el cual busca dar a conocer las diferentes técnicas para el procesamiento de las frutas y hortalizas, manejando un lenguaje adecuado para todo público.
Contenidos:

  • Procedimiento para la elaboración de nopalitos en salmuera
  • Procedimiento para la elaboración de licor de ciruela
  • Procedimiento para la elaboración de duraznos en almíbar
  • Procedimiento para la elaboración de ate de membrillo
  • Procedimiento para la elaboración de ate de guayaba
  • Procedimiento para la elaboración de mermelada de manzana
  • Procedimiento para la elaboración de mermelada de piña
  • Procedimiento para la elaboración de mermelada de jamaica
  • Procedimiento para la elaboración de chiles en vinagre
  • Procedimiento para la elaboración de ciruelas en almíbar
  • Procedimiento para la elaboración de mermelada de mango
  • Procedimiento para la elaboración de licor de jamaica
Luciano Pérez Valadez
César Óscar Martínez Alvarado
Fundación Produce Sinaloa
Procesamiento de Frutas y Verduras a Nivel Casero

 
Las frutas y hortalizas contienen gran cantidad de fácil asimilación por el organismo humano; sin año, por lo que cuando abundan en el huerto o en darles un tratamiento o transformación e incrementar su valor económico, y asi puedan guardarse por un período largo, para poder consumirlos en épocas de escasez. Las ventajas del procesamiento y conservación de frutas y hortalizas son aprovechar los excedentes de productos, evitar pérdidas o desperdicios, y utilizar las técnicas adecuadas para la obtención de productos de alta calidad. Cualquier persona podrá aprender a preparar alimentos si conoce como se hacen las conservas: por placer, pasatiempo o para tener una despensa repleta de productos selectos con ingredientes seleccionados de la mejor calidad, pudiendo inclusive, comercializarlos en pequeña escala.
 

M.C. Cecilia García Osorio
Secretaria de Agricultura, Ganaderia, Desarrollo Rural Pesca y Alimentación
Conservación de Frutas y Hortalizas Mediante Tecnologías Combinadas


Las frutas y las hortalizas son productos altamente  perecederos. Comúnmente, hasta un 23 por ciento de  las frutas y las hortalizas más perecederos se pierden debido a deterioros microbiológicos y fisiológicos,  pérdida de agua, daño mecánico durante la cosecha,  envasado y transporte, o a las inadecuadas  condiciones de traslado.Este manual ilustrado explica con gran detalle  técnicas muy sencillas y de bajo costo para obtenerproductos frutícolas de alta humedad (FAH) y productos frutícolas de humedad intermedia (FHI) estables a temperatura ambiente. Fresas, durazno y ananá se conservan enteros, en rodajas y/o como puré mediante la aplicación de factores de conservación en combinación (tecnología de obstáculos o barreras).
 

Stella Maris Alzamora
Sandra Norma Guerrero
Andrea Bibiana Nieto
Susana Leontina Vidales
FAO
2,004
Caracterización química y sensorial de vino artesanal de melón (Cucumis melo L. var. reticulatus Naud., cv. Ovation)

 
En los últimos años la producción de melón (Cucumis melo L.) ha experimentado un notable aumento generando excedentes en el mercado y no siempre se consigue vender a los mejores precios, por lo que los porcentajes de pérdidas poscosecha son altos (Martínez, 2007). El objetivo de esta investigación fue caracterizar química y sensorialmente vino de melón. La intención fue generar una tecnología sencilla para la producción de una bebida alcohólica de alta calidad a partir de este fruto y con ello aportar una alternativa de comercialización en la región Falconiana y otras regiones productoras del país. Los ensayos se condujeron, para las variables químicas, en un diseño completamente aleatorizado con 3 tratamientos. Los vinos se elaboraron a partir de 8 L de jugo puro de melón de concentración inicial de sólidos solubles totales 16, 20 y 25 ºBx, acidez total (5,5 g/L) y pH (3,8) ajustados, respectivamente denominados tratamientos V1, V2, V3 (3 repeticiones). Colocados en fermentadores de 9 L de capacidad, estériles. Inoculados con 1 g/L de Saccharomyces cerevisiae, e incubados a 28 ºC por 10 días; seguido de trasiego, embotellado, encorchado y almacenamiento por 2  meses. El jugo de melón mostró, sólidos solubles totales 8,00 ºBx, acidez total titulable 0,15 % y pH 5,20. Los vinos, respectivamente V1, V2 y V3, presentaron las siguientes características: grado alcohólico 7, 8, 10 ºGL; alcohol metílico 0,008; 0,002; 0,004 g/L; acetato de etilo 0,02; 0,04; 0,08 mg/L; azúcares totales 20, 40, 58 g/L; acidez volátil 0,814; 0,854; 0,815 g/L; acidez total 6,26; 6,08; 6,00 g/L; acidez iónica 4,00; 3,91; 3,93. Se evidenciaron diferencias estadísticamente significativas (p ≤ 0,05) entre los tratamientos. Los 3 vinos de melón cumplieron con los requisitos: grado alcohólico, alcohol metílico, acetato de etilo, acidez volátil y acidez total establecidos en la norma venezolana COVENIN 3342-1997. V1 y V2 presentaron características de vino semiseco y V3 de vino dulce. Sensorialmente, V3 presentó los mejores atributos de color, olor, sabor, limpidez y apariencia, en base a 50 jueces, y bajo un criterio de aceptación global obtuvo la mayor calificación.

C. Padín
J. Goitia
R. Hernández
I. Leal
Revista Venezolana de Ciencia y Tecnología de Alimentos
2,012
Grado de aceptabilidad de Stevia (Stevia rebaudiana B.) en infusión en una bebida de manzanilla (Matricaria chamomilla L.)


Fue evaluado el efecto del tiempo de infusión y concentración de Stevia (Stevia rebaudiana B.) (1-4 minutos y 1-3 g/300mL respectivamente) sobre el grado de aceptabilidad en una bebida caliente de manzanilla (Matricaria chamomilla L). Como diseño experimental se utilizó la Metodología de Superficie de Respuesta con un Diseño Compuesto Central Rotacional (DCCR) a través de 11 ensayos. Hojas de Stevia, fueron secadas en estufa a 40°C por 24 horas, posteriormente sometidas a molienda manual, envasadas en diversas proporciones en las bolsitas filtrantes y sometidas en infusión por diferentes tiempos en una bebida de manzanilla. La evaluación del grado de aceptabilidad, se realizó mediante un panel sensorial de 40 panelistas escogidas al azar. Se encontró que el grado de aceptabilidad, presento un modelo matemático de segundo orden, estadísticamente significativo (p<0.05). Los resultados obtenidos mostraron que, para obtener una mayor aceptabilidad de Stevia en una bebida de manzanilla, los rangos óptimos en cuanto al de tiempo de infusión y concentración son de 120-160 segundos a 1.8-2.2 g/300 mL respectivamente.

Víctor Vásquez-Villalobos
Raul Blas
Luis Collantes
Marlon Echevarría
Carlos Gordillo
Neiver Guerrero
Roberto Rodríguez
Julia Vásquez
Agroindustrial Science, Universidad Nacional de Trujillo, Perú
2,012
Potencial de recuperación de aceite a partir de pulpa de asaí (Euterpe olerácea Mart.) producido en el pacífico colombiano


La palmera de asaí, (Euterpe oleracea) es una palmera nativa del norte de Sudamérica, que actualmente se aprovecha en el pacifico colombiano para la producción de palmito, sin embargo se reconoce también por su nutritivo fruto. El objetivo de este estudio fue determinar el potencial de recuperación de aceite, el perfil ácidos grasos, el contenido de taninos, polifenoles, antocianinas, la capacidad antioxidante y el color de la pulpa del asaí, colectada en el pacífico colombiano. Para el análisis proximal se utilizaron métodos oficiales, los polifenoles, taninos y antocianinas se determinaron por espectrofotometría y la actividad antioxidante se midió por el método de reducción de hierro (FRAP). Los resultados expresados en base seca indicaron que el asaí tiene un alto contenido de lípidos de 49,4%, proteínas 9,3%, cenizas 2,2%, y fibra dietaría total de 20,0%. Es importante destacar que más del 60% de los ácidos grasos corresponden a ácido oléico, el contenido de polifenoles fue de 3,06 g/100 g; taninos de 1,45 g/100 g; antocianinas 1,80 g/100 g y la capacidad antioxidante fue de 787. 37 μMol/L de Trolox. Se concluye que el asaí recolectado en el pacífico colombiano tiene un alto valor nutricional y contiene compuestos antioxidantes valiosos que lo hacen un material promisorio para su comercialización y así aprovechar al máximo sus propiedades.

Ligia Inés Rodríguez
Lorena Hasbleidy Ramírez
Revista Alimentos Hoy, Asociación Colombiana de Ciencia y Tecnología de Alimentos
2,013