scholarly journals Effect of Preparation and Storage Conditions on Physical and Chemical Properties of Puree, Puree Juices and Cloudy Juices Obtained from Pumpkin with Added Japanese Quince and Strawberries

Author(s):  
Agnieszka NAWIRSKA-OLSZAŃSKA ◽  
Anita BIESIADA ◽  
Anna SOKÓŁ-ŁĘTOWSKA ◽  
Alicja Z. KUCHARSKA
2016 ◽  
Vol 44 (1) ◽  
pp. 183-188 ◽  
Author(s):  
Agnieszka NAWIRSKA-OLSZAŃSKA ◽  
Anita BIESIADA ◽  
Anna SOKÓŁ-ŁĘTOWSKA ◽  
Alicja Z. KUCHARSKA

When evaluated in terms of taste, smell or active ingredients, pumpkin in itself is not very attractive as a raw material. Hence it seems recommendable to blend pumpkin with other fruits. The pumpkin chosen for the experiments was of the variety ‘Karowita’. The aim of the study was to compare the physical and chemical properties of pumpkin samples based on different storage conditions. Pumpkin puree, puree juice and cloudy juices containing Japanese quince and strawberries were evaluated for their physical and chemical properties initially and after three months storage at temperatures of 4 °C and 30 °C. Cloudy juices were prepared with pectolytic preparation. The extract dry matter in all the samples was at a similar level. Puree and puree juice had considerably higher viscosity than cloudy juices. The highest quantities of bioactive compounds were detected in slightly processed samples (puree, puree juice and cloudy juices) stored at 4 °C . Increased content of polyphenols was observed in puree and puree juice after storage. However, in the remaining samples, there was observed a decrease in the content of the compounds. A considerable decrease in carotenoids took place in samples subjected to pressing, where the amount of assayed carotenoids in puree was 5.24 mg/100 g fresh matter (FM), 4.15 mg/100 g FM in puree juice, and 0.18-0.47 mg/100 g FM in cloudy juices. The pressing also caused a significant decrease in colour parameters. Three months of storage showed markedly decreased contents of carotenoids and vitamin C.


2021 ◽  
Vol 2(73) (1) ◽  
pp. 90-99
Author(s):  
Renata Rădulescu ◽  
Timur Chiș

"Extracted oils and gases have different physical and chemical properties, depending on oil structures. Thus, it is beneficial to create mixtures of oils by combining cheaper crude oils with variants that have better properties (Brent type). This will result, in a reduced cost of acquisition. Mixing crude oil (obtaining blend crude oil) is a process in constant development, so that new ways for improving crude oil properties can be surfaced and to create new ways for transport and storage with lower costs. As an example, by mixing crude oil we can ensure viscosities and freezing conditions for certain transport systems. The aim of this paper is to present the techniques for mixing crude oil, the study of technologies, equipment needed for it and the numerical models for obtaining optimal mixing rates. "


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