International Journal of Research and Innovation in Applied Science (IJRIAS) |Volume VIII, Issue I, January 2023|ISSN 2454-6194
Adekunle Adebo Ajayi1*, Ibukun Caroline Vining-Ogu1, Xavier Chizimuzo Akalonu1, Jeremiah Garba Danladi1, Tamunotonye Abel Briggs2
1Biochemistry Unit, Department of Science Laboratory Technology, Akanu Ibiam Federal Polytechnic, Unwana, Ebonyi State, Nigeria
2Microbiology Unit, Department of Science Laboratory Technology, Akanu Ibiam Federal Polytechnic, Unwana, Ebonyi State, Nigeria
*Corresponding author
Abstract- The effects of storage on selected organic acid in some commonly consumed natural fruit juices were examined. The fruits (cucumber, water melon, soursop, grape, orange, lemon, and lime) were randomly selected and their juice extracted and store at 250 C. Analysis for acetic, citric and lactic acid were done for 5 days using standard method of analysis. The acetic, citric and lactic acid concentrations showed days dependent increase in all the natural fruits juice from days 1-5. However, acetic, citric and lactic concentrations increased mostly in lime juice on days 3 and 4. While on day 5, all the organic acids gave highest concentrations in orange juice compared to other fruit juices. This study revealed that continuous storage of fruit at room temperature might increase the concentration of organic acid in it.
Keywords: organic acid, fruits, orange, acetic acid, citric acid
I. Introduction
Organic acids are naturally occurring compounds which are abundantly present in different fruits, plants and vegetables. Fruits are renowned sources of natural organic acids, and these acids have wide spread usage such as food decontaminants practiced from very early times [1]. Organic acids are volatile or non-volatile compounds used in variable quantities in various foods and beverages with undeniable contribution in maintaining taste and quality of the product [2], [3].
Organic acids have extensive usage in foods and beverage processing as pH adjusting agents, flavourings and acidulants [3]-[5]. Thus, enhancing organoleptic properties in food. Some gotten from citrus fruits act as promising antioxidants and have potential to replace artificial antioxidants used in various products. They are useful indices of authenticity or adulteration in fruits products, since they have lower susceptibility to change during processing and storage than other components of the fruits [6].
The acid content of foods directly affects their flavour and practically all foods contain an acid or a mixture of acids. these acids may occur naturally, may be produced by action of micro-organisms, or may be added in such products e.g catchup or chilli sauce during their production [7]. In some cases, a high concentration of acid may be an indication of spoilage and rancidity while in other cases high acid content is necessary for preservation. The concentration of these acids could be affected largely by handling, storage temperatures and microorganisms. Overall, total acidity content determination in foods is useful as a measure of this tartness.
Therefore, this study aims to determine the estimate of selected organic acids in some common fruits in order to assess the level of the acids when the juices are stored at room temperature.
II. Materials and Methods
A. Preparation of Samples
The fruits (cucumber, water melon, soursop, grape, orange, lemon, and lime) used for the study were fresh, randomly selected and purchased from the fruit vendors at market (Eke Market Afikpo) in Ebonyi State. They were cut to sizeable oval shape and juice extractor was used to squeezed out and obtain the juice. Then the juice were filtered with cheese cloth and further filtered with whatmann filter paper and the clear liquid obtained were stored at 250C and used for analysis within 5 days.
I) Preparation of 0.1 NaOH: Four grams (4g) of sodium hydroxide (NaOH) was weighed out, and was dissolved with 1000ml distilled water in a volumetric flask. This was used for the titration.