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Microbiological control of dried fruit
Smolíková, Marie ; Popelářová, Eva (advisor) ; Šlapáková, Barbora (referee)
An important factor for assessing the quality of food is their microbial contamination. This Bachelor thesis deals with the microbiological quality of dried apples. Bachelor thesis is based on the assumption that the use of sulphites has influence of the content of microorganisms. The aim is therefore determine their number, the influence of use of sulphites on their content, eventually evaluate other effects of sulphites on dried apples.
Consuming food without additives is a trend of current time. If we are talking about dried fruit, additives are sulphites, which prevent primarily darkening of apples, they are used like preservatives, but they are allergen. So that is the reason why are Bio apples often coveted.
In the practical part were compared apples which were not sulphurized, apples which were sulphurized and Bio apples, which were made in Severofrukt a.s., Trávčice. It was used six samples of each type. In all samples were determinated total amount of microorganisms - CPM, amount of coliform bacterias, Escherichia coli, yeasts and molds. Assessment was performed on Petrifilms from NOACK Company. Samples were also sent to be compared to acredited labaratories. Next thing, which was done, was examination, if the use of sulphites has any other effects on dried apples.
All of samples fulfilled requirements of the Decree. In any of samples were not proven coliform bacteries or E.coli. According to analyzes Bio apples had the highest content of undesirable microorganisms. The total amount of microorganisms at them was in the average 11 000 KTJ/g. Sulphurized apples were less contamined than aplles, which were not sulphurized. The difference was almost about one half. This shows, that the use of sulphites has a positive influence on the content of microorganisms. And with the use of sensory evaluation was proved, that the use of sulphites has inluence on a colour of dried apples.
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Zpomalení zralosti odrůdy Golden Delicious účinkem 1-MCP během chladírenského skladování
Koláčková, Veronika
Diploma thesis was prepared at the Department of Post-Harvest Technology of Horticultural Products at the Faculty of Horticultural of the Mendel University in Brno in years 2014-2015. The goals of this thesis was evaluated parameters which can best recognize function of 1-MCP. Function of 1-MPC was evaluation by set up by soluble solids, titratable acid, flesh firmness, ethylene production, intensity respiration and weight loss. The theoretical part of thesis deals with general characteristics of apple, substance composition of the fruit, characteristic of ethylene and 1-MCP effect on climacteric fruits.
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Změny fyzikálně chemických vlastností chladírensky skladovaných jablek
Vojtěšková, Darja
Physical and chemical changes during maturation of apple tree and in post-harvest changes play an important role. The aim was to focus on these changes and subsequently evaluated. In the literary part of the thesis is focused on chemical and nutritional aspects fruit ripening and respiration fruits, harvest, storage options and physiological disorders during storage. In the practical part were evaluated three varieties of apples "Rubinola, Prima and Topaz." First, the fruits were evaluated during ripening on the tree. For each variety were taken each five fruits every 7 days. The optimum ripeness was collected 40 varieties of each fruit and the cold storage for 90 days at a temperature of 3 °C. According to the qualitative characteristics of those properties (starch test, soluble solids and titratable acid) and mechanical-physical properties (penetrometer strength, weight) were measured varieties and subsequently evaluated.
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Assessment of aroma active compounds in cultivars of apples
Mahdalová, Martina ; Trachtová, Štěpánka (referee) ; Vítová, Eva (advisor)
The aim of this master‘s thesis was to determine the aroma active compounds and monitor the sensory quality of apples. The theoretical part deals with the description, composition and properties of apples, information about the aroma compounds, their determination and possibilities for sensory evaluation of apples is also given. The gas chromatography method combined with the solid-phase microextraction, utilized for the specification of aroma compounds, is described. In the experimental part, the SPME-GC-FID method was applied on selected cultivars of apples specially cultivated against apple scab (Venturia inaequalis), i.e. 24 genotypes and Golden Delicious as the control variety. In total 60 various aroma compounds were identified, 22 alcohols, 12 aldehydes, 11 ketones, 10 esters and 5 organic acids. The number and concentration of compounds identified differed according to the cultivars. Sensory analysis was performed using category ordinal scales and the profile test.
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Study of fruit ripening and storage
Langová, Jiřina ; Zemanová, Jana (referee) ; Babák, Libor (advisor)
There are many changes in fruit quality during its ripening and storage. The following four apple varieties were studied: Champion, Glostr, Golden Delicious and Idaret. Amount of reducing sugars, total amount of sugars, quantities of acids, refractive solids and loss of starch were monitored. The changes of parameters, the differences between the varieties and differences in storage were compared. Parameters were monitored from mid-August 2008, when the apples ripened. After the harvest, apples were stored in a cool box at 2 - 3 ° C and at room temperature 20 - 23 ° C. Apples stored in the cool box were analyzed till the end of March 2009, and apples stored at room temperature until the beginning of January 2009. Total quantity of sugars in all varieties increases before harvest, while it decreases after picking the apples. The quantity of reducing sugars in apples rises gradually and after their picking it falls significantly in apples stored at 20 - 23 ° C. In apples stored in the cool box it continues rising until the end of November, and then it also decreases. Losses of starch are considerable and they are accelerated after the harvest. The quantity of acids also decreases throughout and amounts of refractive solids increases. For all varieties there are significant changes in storage at 20 - 23 ° C. Temperature, therefore, significantly affects processing of sugars and acids in fruit respiration.
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Influence of storage conditions on content of biologically active substances in apple fruits.
Ferdová, Jitka ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This study deals with antioxidants in diet and their effects on human organism. Further, it summarizes the agents affect the quality of apples in the course of long-term storage and it outlines the possibility of defence against them. In the experimental part methods of determination of antioxidant enzymes superoxid dismutase (SOD), catalase and polyphenol oxidace (PPO) in apples were introduced. The enzymes were measured in apples tissues in liquid nitrogen after 158 days in normal or modified atmosphere. In Apple the quantitative and qualitative analysis of proteins was realized. Further, some low molecular antioxidants (total phenolics, total flavonoids and vitamin C) as well as total antioxidant status were measured in frozen raw juice. This values were compared with values from apples analyzed immediately after the harvesting. Artificial inoculation with fungi was made in the last part and the fruitfulness was observed.
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Způsoby a metody zpomalování zralosti jablek
Majorová, Anežka
Three cultivars of apple (Idared, Prima, Golida) were harvested in three stages of ri-peness (unripe, ripe, overripe) that were stored for 30 days in two different temperatures (2 °C a 20 °C). On all cultivars, the ripeness was studied during the storing based on objective measurements. The performed measurements enabled to determine 3 basic criteria (penetration stress, soluble solids, acid-based titration). From the stored cultivars, Prima was ripe in the time of measurement, cultivars Idared and Golida reached similar in descibed parameters that are stated by the average and standard deviation. The aim of this work was to find optimal ripeness of apples, especially for long-term storage. Knowing of materiál composition during the harvest was important for studying of ripeness. The changes and values are observed and recorded. According to these values, the conditions for every cultivar for long-term storage and maintenance of apples at optimum ripeness are determined.
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Stanovení sklizňového termínu jablek
Suková, Barbora
The goal of this thesis which is called "Determination of the harvest date of apples" was find out a dependences between fabric components during maturation period. Four species of apples were selected (Idared, Golida, Topaz and Golden Delicous) in practise part. The samples were collected in eight terms. From each cultivar was taken five fruit. The fruits were analysed by quality parameters (titrable acids, soluble solids, firmness of the flesh and determination of starch). The main goal was identify the most appropriate parameter for assessment maturity at given cutivars. The basic parameter of apples were desribed in theory part, then better storage of fruit, new trends in storage or physioloical disease of apples in storage. Methods to determine the date of matury are described (Streife index, measuring the activity of physiological important gases).
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