Academic literature on the topic 'Fruit - Preservation - Drying'

Drying is one of the oldest methods for food preservation that removes the water from fruit and makes it available for consumption throughout the year. Dried fruits can be produced by small- and large-scale processors, which makes them a very popular food among consumers and food manufacturers. The most frequent uses of drying technology include osmotic dehydration, vacuum drying, freeze-drying and different combinations of other drying technologies. However, drying may provoke undesirable changes with respect to physiochemical, sensory, nutritional and microbiological quality. Drying process energy efficiency and the quality of dried fruits are crucial factors in fruit drying. Recently, innovative technologies such as ultrasound, pulsed electric field and high pressure may be used as a pretreatment or in combination with traditional drying technologies for process intensification. This could result in quality improvements of dried fruits and enhanced efficiency and capacity of the production process, with a positive impact on environmental and economic benefits.

Drying is one of the oldest methods for food preservation that removes the water from fruit and makes it available for consumption throughout the year. Dried fruits can be produced by small- and large-scale processors, which makes them a very popular food among consumers and food manufacturers. The most frequent uses of drying technology include osmotic dehydration, vacuum drying, freeze-drying and different combinations of other drying technologies. However, drying may provoke undesirable changes with respect to physiochemical, sensory, nutritional and microbiological quality. Drying process energy efficiency and the quality of dried fruits are crucial factors in fruit drying. Recently, innovative technologies such as ultrasound, pulsed electric field and high pressure may be used as a pretreatment or in combination with traditional drying technologies for process intensification. This could result in quality improvements of dried fruits and enhanced efficiency and capacity of the production process, with a positive impact on environmental and economic benefits.

There are about 68 types of mulberry fruit with a wide ecological production area. Different mulberry species are grown in large fields in Turkey. Mulberries are largely dried-consumed, but sometimes they are used as fruit juice. In this study, black mulberry fruit was collected in two different ripening levels (semi-ripe and full-ripe) and oven-dried at 50, 60 and 70°C drying temperatures. Initial moisture contents of semi-ripe and full-ripe fruits were determined as 86.74% and 82.95%, respectively. Fruits were dried to have final moisture levels of 10-15%. Drying duration, drying models, effective diffusion, activation energy, specific energy consumption, color parameters and chemical properties of dried fruits were examined and the effect of ripening levels and drying temperatures were investigated. In terms of drying duration, while full-ripe fruits dried in a shorter time, effective diffusion, activation energy and specific energy consumption values were found to be higher than semi-ripe fruits. In terms of color parameters, semi-ripe fruits are recommended to be dried at 50 or 60°C drying temperatures and full-ripe fruits should be dried at 50°C drying temperature for better preservation of color parameters. On the other hand, a common proper drying temperature could not be identified for acidity (pH), water soluble dry matter and titratable acidity.

Argan oil is extracted from the kernels of argan fruits that have been sun-dried for either a few days or up to several weeks. The influence of the fruit drying time on the quantity, quality, and preservation of solvent-extracted argan oil was compared with press-extracted argan oil. Quantitatively, the time necessary for efficient fruit peeling and the amount of extracted oil were determined with regard to the fruit drying time (0 to 28 days). Argan oil quality was studied using, as markers, moisture content, specific extinction, acid index, peroxide index, fatty acid composition, and Rancimat oxidative stability. Oil from fresh fruit presents a high moisture content, high acidity and peroxide values, and short shelf life. Ten to fourteen days of sun-drying is optimum to obtain high quality argan oil.

The aim of this paper is to demonstrate that procedures and methods of conservation are very important for the production of good and quality fruit products. The use of preserving methods is essential in order to preserve the quality for a long period of time in most fruit products. Conservation methods are divided into three groups: physical, chemical and biological methods. In these methods, the temperature and the quality of the raw materials are very important. In order to obtain various fruit juices, pulps, various fruit products, all the conditions and in particular the method, method, temperature and conservation conditions must be taken into account. The most common and most used methods are pasteurization, sterilization, drying and freezing. In the pasteurisation method, latent heat and air effect must be taken into account, which directly affect the quality of the products obtained by this method.

The article raises the question of the need to solve the drying and storing fruits problem. The actuality of drying is the simplest and most economical method of fruit preservation. The analysis of recent studies and publications devoted to the consideration of theoretical and practical aspects of the development of fruit drying is made and highlighted in the works of domestic and foreign scientists. Drying plants main requirements are given. Methods of fruit drying are considered. The goals and necessity of carrying out experiments to study the influence of changes in air temperature and air velocity on the drying process are formulated. The main conditions for obtaining high-quality raw materials at the output in a short period of time with minimal energy consumption have been determined. The design of a convection dryer chamber in which experiments were carried out in the laboratory of the Department of Heat and Gas Supply, Ventilation and Heat Power Engineering of the National University "Yuri Kondratyuk Poltava Polytechnic" is presented. The results of its verification for aerodynamic and thermal performance are presented. Drying plums experiments, their analysis and comparison have been spent. The most expedient variant of plum drying was chosen. The main conclusions based on the results of the conducted field laboratory experiments are made. The necessity and prospects of further research on fruit drying have been proved.

Fig is one of the oldest fruit species cultivated in the Mediterranean basin, and it can be widespread in warm and dry climates around the world. Turkey is the primary producer and the tree can bear up to two crops per year which is depending upon the fig type, quality can be differing from season to season. Figs can be eaten fresh, dried, or processed into different types of products. They are low in organic acids and high in sugars so it is sweet-tasting fruit. Their phenolic content is medium and higher in red cultivars which hold high levels of anthocyanins. The total carotenoid in the fig is quite low and mostly concentrated in the fruit's peel when compared with other fruits. Fruit drying is the easiest way of fig fruit preservation. The traditional sun-drying method yields produce with diverse quality. Automated air dehydration has several advantages and makes fruit with high sugar content and high total phenolics. Anthocyanins and carotenoids are lost during the drying process. The consumption of figs should be encouraged as it contains high beneficial effects and potential healthy alternative for sweets.

The demand for food has been ever increasing in proportion with the growing human population. This includes agricultural products including fruits. Hence, food preservation for extended usage through drying is gaining importance. This study reports the drying behavior of several agricultural products, namely sweet potato, carrot, ginger, turmeric, passion fruit and its rind. Focus has been given to the effect of relative humidity on drying for these products at room temperature. Experiments were carried out at 27°C by varying relative humidity at 40%, 60% and 80%. It was found that the relative humidity has a strong effect on drying, with lower relative humidity providing higher drying rates. In humid surrounding like Malaysia which has an average humidity more than 70%, controlling humidity of drying air may result in an energy efficient process in comparison to raising the drying air temperature

<p>‘Murtilla’ (<em>Ugni molinae</em> Turcz) is a native Chilean species that belongs to the Myrtaceae family. It produces a small, globular fruit with pleasant flavor and recognized antioxidant activity. Convective hot-air and freeze drying are important techniques for fruit preservation, but their effect on murtilla fruit polyphenols and antioxidant activity has not yet been studied simultaneously. The objective of this study was to compare the effect of convective hot-air drying at 65 and 80 ºC and freeze drying on total polyphenol content (TPC), total anthocyanin content (TAC), polyphenols and anthocyanins of the Red Pearl-INIA variety of fresh murtilla fruits as measured by HPLC and antioxidant activity (DPPH and ABTS). The freeze dried fruit retained higher values for TPC (2192.4 mg/100 g d.w.), TAC (13.4 mg/100 g d.w.), polyphenols (79.02 mg/100 g d.w. by HPLC) and anthocyanins (0.188 mg/100 g d.w. by HPLC) than the murtilla dried by convective hot-air at both 65 and 80 ºC. The application of all treatments showed a positive increase in the DPPH (2945.4 to 3677.6 ?mol TE/100 g d.w.) and ABTS (2664.8 to 3397.2 ?mol TE/100 g d.w.) antioxidant activity of the dried murtilla compared to the DPPH (2111.1 ?mol TE/100 g d.w.) and ABTS (2247.8 ?mol TE/100 g d.w.) of the fresh fruit. Freeze drying was the best technique for the retention of polyphenols and antioxidant activity from the fresh murtilla fruit. Therefore, freeze drying is recommended over convective hot-air drying at 65 and 80 ºC when these bioactive compounds need to be preserved.</p>

Orientador: Ana Maria Frattini Fileti
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: A pimenta-rosa, produzida a partir dos frutos da aroeira-vermelha (Schinus terebinthifolius Raddi), é um dos mais sofisticados condimentos da culinária internacional e que vem apresentando um aumento na sua demanda. No entanto, na literatura encontram-se poucos estudos sobre o seu processamento, em que a secagem é uma etapa indispensável e que ainda é realizada de forma empírica. Nas empresas beneficiadoras, a etapa de secagem tem por finalidade aumentar a vida de prateleira do produto, além de agregar valor aos frutos da aroeira-vermelha. Neste contexto, este trabalho teve por objetivo realizar investigações no processo de secagem de frutos de aroeira-vermelha, focando principalmente no estudo de modelos matemáticos para a simulação do processo. As amostras de frutos de aroeira-vermelha, utilizadas nos ensaios de caracterização e secagem, foram classificadas manualmente e reumidificadas artificialmente. Para a caracterização do sistema particulado, os seguintes parâmetros foram determinados: teor de umidade em base seca; diâmetro médio e massa específica aparente dos frutos; e massa específica e porosidade do leito de frutos. Também foram determinadas, através do método estático, as isotermas de dessorção de umidade dos frutos em temperaturas de 30, 50 e 70 ºC. Um Delineamento Composto Central Rotacional (DCCR) com 11 experimentos foi desenvolvido e foram investigadas as influências da temperatura (40 a 70 ºC) e da velocidade do ar de secagem (0,4 a 0,8 m/s) no processo. Em cada um dos ensaios do DCCR foram analisadas a cinética de secagem e a curva de taxas de secagem dos frutos de aroeira-vermelha. Os modelos de difusão, de Lewis, de Henderson e Pabis, de Page modificado e de Henderson foram ajustados aos dados experimentais da cinética de secagem, sendo realizada a comparação destes modelos com um modelo fundamentado na Inteligência Artificial. Os resultados revelaram que, para as condições operacionais estudadas neste trabalho, a temperatura do ar de secagem apresenta uma influência maior no processo. A cinética de secagem ocorre principalmente no período de taxa decrescente. Isto indica que a secagem ocorre pela remoção da umidade interna do sólido. O modelo via Redes Neurais Artificiais (RNA's) e o modelo de Henderson apresentaram os resultados mais satisfatórios no ajuste aos dados da cinética de secagem dos frutos de aroeira-vermelha. No entanto, observou-se que a principal vantagem do modelo de RNA, em relação aos modelos clássicos, foi a sua generalidade. O modelo de RNA foi capaz de descrever uma série de experiências com precisão, enquanto que a aplicação de modelos clássicos foi limitada a uma experiência específica. Para o modelo neural, esta gama de condições experimentais pode ser expandida através da adição de novos conjuntos de experimentos de treinamento. Deste modo, os resultados satisfatórios da utilização de um modelo baseado em RNA's em processos de secagem indicam a potencialidade da aplicação desta ferramenta na modelagem de processos industriais de secagem
Abstract: The pink pepper, produced from the Brazilian pepper-tree fruits (Schinus terebinthifolius Raddi), is one of the most sophisticated condiments of the international cuisine. The demand for pink pepper is increasing because it adds taste and refinement to international cuisine. Until now, rare are the studies that investigated the drying of Brazilian pepper?tree fruits. In the processing companies, the process is carried out empirically and the drying operation is an important step. The Brazilian pepper?tree fruits are dried to inhibit microbial development and quality decay. Another benefit of drying is a reduction in weight. In this context, this study aimed to perform investigations in the drying process of Brazilian pepper?tree fruits, focusing mainly in the study of mathematical models to simulate drying kinetics. Before each test, the fruits were sorted manually and humidified artificially. In this study, physical characterization of Brazilian pepper?tree fruits was obtained by evaluating the moisture content on dry basis; mean diameter and apparent density; bulk density and porosity. The moisture sorption isotherm, at temperatures of 30, 50 and 70 ºC, were determined by the static method. A Central Composite Rotable Design (CCRD) with 11 experiments was developed. In each experiment, the drying kinetics and the drying rate were investigated, as well as the influence of input variables on the drying process. Classical models were fitted to the drying data, as well as a model based on Artificial Intelligence. In the operating conditions of this study, the results revealed that the air temperature has a greater influence on the thin layer drying process of Brazilian pepper?tree fruits. The drying kinetics occurs mainly in the falling-rate period of drying. This indicates that drying occurs mainly by removal of internal moisture of the solid. The artificial neural network model and the Henderson model fitted to the experimental data more accurately in comparison to the various mathematical models. However, it was observed that the main advantage of the artificial neural network model over classical models was their generality. The ANN model was able to describe a range of experiments accurately, while the application of classical models is limited to a specific experiment. For the neural model, this range of experimental conditions may be expanded by addition of new sets of experiments in training
Mestrado
Sistemas de Processos Quimicos e Informatica
Mestre em Engenharia Química

This study investigated the quality and safety of solar dried fruits and vegetables produced by households in three locations in the Butha-Buthe district of Lesotho from November 2002 to March 2003. The aim of the study was to enhance year round availability of fruits and vegetables and reduce post-harvest losses, contributing to increased food availability and accessibility in the district. The study analysed the quality and safety of dried fruits and vegetables by assessing the processing techniques applied by the respondents during the production of dried fruits and vegetables, analysing the quality of dried fruits and vegetable samples produced by the study respondents using Appropriate Technology Section (ATS) solar driers, and by identifying the constraints that hamper the improvement of quality and safety of solar dried fruits and vegetables in the study area. Data was collected through focus group discussions, interviews, and laboratory food quality analysis of dried fruit and vegetable samples provided by the respondents. The dried fruits and vegetables produced by the respondents were of low quality due to poor processing techniques and unhygienic practices that increased chances of contamination and deterioration during processing and storage. Lack of processing skills and information, particularly on quality and safety standards, and weak extension support contributed to poor product. For the respondents to improve the quality and safety of dried fruits and vegetables, they need training and support with respect to quality and safety that includes training on the importance of food safety, best processing and storage practices and marketing of dried produce.
Thesis (M.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

Solar Air Drying is one of the oldest method of food preservation. For several thousand years people have been preserving grapes, herbs, Potato’s, corn, milk, fruits, vegetables, spices, meat and fish by drying. Until canning was developed at the end of the 18th century, drying was virtually the only method of food preservation. It is still the most widely used method. Solar Drying is an excellent way to preserve food and solar food dryers are an appropriate food preservation technology for a sustainable world. This technology makes it possible to dehydrate and preserve food professionally without compromising on quality, color, texture, enzymes, vitamins, taste and nutritional values of foods in the process. Food scientists have found that by reducing the moisture content of food to between 10 and 20%, bacteria, yeast, mold and enzymes are all prevented from spoiling it. India is blessed with an abundance of sunlight, water and biomass. Vigorous efforts during the past two decades are now bearing fruit as people in all walks of life are more aware of the benefits of renewable energy, especially solar energy in villages and in urban or semi-urban centers of India. Industries that can benefit from application of solar energy to heat air are Food, Textiles, Dairies, Pharma and Chemical. This paper reviews the present scenario of Solar Air Dryer and strategies for future developments in India.