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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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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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Geographical Aspects of Fruit and Vegetable Industry: Czechia in a Global Context
Járová, Hana ; Novotný, Josef (advisor) ; Kabrda, Jan (referee)
This thesis has two basic aims. The first aim is to analyze the global value chain of fruits and vegetables and the current international market with apples. The second aim is to analyze the value chain of apples in Czechia and measure its connection to global value chains. The research was carried out by analyzing secondary sources and basing on an own qualitative survey. This thesis is divided into two major parts. The first part deals with the global value chain (GVC) of fruits and vegetables. This chain is examined through five dimensions which are typical for GVC analysis: input-output structure, geographic scope, governance, institutional context and upgrading. The second part focuses only on one specific crop, apples. Firstly, it is studied at the global level, then the thesis concentrates only on the value chain of apples in Czechia.
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Studium vlivu podmínek sušení na senzorické parametry
Fajgara, David
This bachelor thesis focuses on different drying methods, moisture content of food and overview of sensory evaluation. The experiment was conducted on four different types of apples (Evelina, Red Prince, Golden Delicious and Spartan). The drying process was performed by two methods with various temperature and time settings (food dryer set to 35 °C, 55 °C, 70 °C and freeze-drying for 48 hours, 72 hours and 168 hours). The evaluator evaluated the shape, color, smell, taste, consistency and overall impression of dried apples. The best results were obtained with freeze-drying for 72 hours, which succeeded in most categories, including the overall impression. The results of various methods, temperature and time settings differed by 40 %, which means apples dried in freeze-drying process were almost two times as attractive as apples dried in food dryer.
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Výběr vhodných starých odrůd jablek pro moštování v oblasti Podesní
Kotrašová, Petra
Selection of suitable old varieties of apples for stumming in Podesní. There were mapping locations with presence of old varieties of apples in the area. Trees were evaluated. There were selected varieties of fruits stored and then processed with stumming from these locations. Musts of different varieties such as ´Moravská Jadernička´ and also other varieties, a mixture of several varieties were tasted and evaluated. Varieties ´Strýmka´, ´Jadernička Moravská´, ´Malinové Hornokrajské´, ´Sudetská Reneta´ are in terms of our mapping suitable for planting and for subsequent processing of musts in Podesní.
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Geographical Aspects of Fruit and Vegetable Industry: Czechia in a Global Context
Járová, Hana ; Novotný, Josef (advisor) ; Kabrda, Jan (referee)
This thesis has two basic aims. The first aim is to analyze the global value chain of fruits and vegetables and the current international market with apples. The second aim is to analyze the value chain of apples in Czechia and measure its connection to global value chains. The research was carried out by analyzing secondary sources and basing on an own qualitative survey. This thesis is divided into two major parts. The first part deals with the global value chain (GVC) of fruits and vegetables. This chain is examined through five dimensions which are typical for GVC analysis: input-output structure, geographic scope, governance, institutional context and upgrading. The second part focuses only on one specific crop, apples. Firstly, it is studied at the global level, then the thesis concentrates only on the value chain of apples in Czechia.
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Usage of the product in school canteens
Vodička, Jan ; Šánová, Petra (advisor) ; Hrubcová, Barbora (referee)
The thesis is focused on the consumer interest in a new product on the market, for this purpose, freshly chopped apples in a hygienic bag with a shelf life of 12 days. The aim of this thesis is to determine whether school representatives will show interest in this product or not. The methodology of the work itself involves the creation and evaluation of two questionnaire surveys, which were attended by 69 school representatives and 116 parents of children aged 3 to 15 years. The results of the survey have shown that these schools cannot offer children fresh, washed, hygienically prepared fruit, designated for direct consumption on field-trips, sporting events, etc., hence they would be willing to buy this new product for children in schools. The questionnaire survey, which concerned children's parents, showed that parents do not find the offer of fruit and healthy food in schools sufficient and they would like this product to be sold mostly in school cafeterias and snack machines.
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Evaluation of selected qualitative parameters of apples produced under different growing methods
Dresslerová, Ivona ; Kouřimská, Lenka (advisor) ; Jan, Jan (referee)
The most spread system of agricultural production is conventional system, which reaches the best profits by its excessive inputs into production such as fertilization, chemical spraying, heavy engineering. However the importance of ecological (BIO) and integrated (I.P.) production has been increasing among the consumers recently. Mainly because of environmental sustainability and protection of their own health. The aim of this study is to compare qualitative characteristics of 10 different apple cultivars (Melodie, Šampion, Gloster, Idared, Angold, Topaz, Goldstar, Ontario, Florina, and Rubín) with reference to the type of production system. The dry matter content, amount, concentration of carbohydrates, ascorbic acid, sensory evaluation and overall profile of volatile compounds were analysed in apples coming from both ecological and integrated agriculture.
The dry matter content of all apple cultivars was measured by using two different methods. At the same time drying in an infra-red scale and refract metrical measuring by a portable refractometer were carried out. Concentrations of different carbohydrates (sucrose, glucose and fructose) were analysed by HPLC method with RI detection. The content of ascorbic acid (AA) was determined by HPLC with UV/VIS detection. During the sensory evaluations a protocol for a trained sensory panel was created including profile, pair and pair preference test. With an aim of detection of volatile aromatic compounds´ profile there was a sorption prepared on SPME extraction with following analysis on GC-GC-MS.
In the concentration of C vitamin was the cultivar found statistically significant (p = 0,0004) and not in the supposed type of production. The final concentration of ascorbic acid was 13-130 mg/kg in BIO apples and 10-103 mg/kg in apples from integrated production. Overall 7 BIO cultivars had higher content of AA in comparison to I.P. The highest concentration of AA was in cultivar Ontario. In total 7 BIO cultivars from 10 had bigger content of AA in addition to integrated samples. The most present carbohydrate in apples is fructose in which was found a statistically significant difference between values of BIO and I.P. (p = 0,0272). The highest figure of fructose and also of sum of sugars was Angold BIO (422,3 g/kg). The highest presence of dry matter was found in cultivar Florina BIO (18,62 %). Refract metrical matter was in the range from 11 to 17 Brix.
There was a statistically significant importance proved between the figures of BIO and I.P between both dry matters. At the same time it was proved that there is present a dependence between them based on correlation coefficient (r = 0,9622). It was assumed that the overall sum would correlate with refract metrical dry matter, but this was not confirmed. There was also proved a statistical difference (p = 0,0002) between the BIO and I.P apple weights. In all cases of samples the weights of I.P apples was higher. In sensory analysis the cultivar Šampion BIO was evaluated the best from the overall intensity and pleasure of the taste.
Topaz I.P was evaluated as the sample with the most pleasant taste and Florina I.P with the highest taste intensity. By the analysis of pair preference test results it was confirmed that there is a statistically significant difference on the selected level of probability 99%. But preference in any of production systems was not confirmed. During the analysis of overall profile of volatile aromatic substances it was found out that the same cultivar of different production has the same composition, but different relative concentration of the present substances.
This problematics needs further and more detailed analysis, which would prove or disprove influence of the cultivar on all analysed aspects.
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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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