The pineapple is one of the leading products in the Philippines, as it thrives in tropical climates. However, the pineapple peelings have low commercial value and are therefore merely thrown away, contributing to the Philippines waste problem. This study entitled “Saccharification of Pineapple Ananas comosus peelings through Dilute Acid Hydrolysis” was conducted to know the concentration of sugar content which can be used for other purposes like bioethanol.
Three samples were used, each sample was composed of two trials; S1T1 (60 degree Celsius for 30 min.), S1T2 (60 degree Celsius for 60 min.), S2T1 (70 degree Celsius for 30 min.), S2T2 (70 degree Celsius for 60 min.), S3T1 (80 degree Celsius for 30 min.), S3T2 (80 degree Celsius for 60 min). The phenol- sulfuric acid method was used to determine the concentration of sugar content present in the substrate. The test revealed that the dilute acid hydrolysis is an effective way and can saccharify pineapple peelings based on the standard curve. However, the temperature and time was found out that they both have no significant difference in yielding greater concentration of sugar as what as the statistical analysis revealed using Kruskal-Wallis test and Mann Whitney U-test.
Background of the study
Pineapple (Ananas comosus) is the common name for a tropical plant and its edible fruit which are coalesced berries. Pineapples are the only bromeliad fruit in widespread cultivation. It can be grown as an ornamental, especially from the leafy tops. Some sources say that the plant will flower after about 24 months & produce a fruit during the following six months while others indicate a 20-month timetable. Pineapple is eaten fresh or canned or juiced. It is popularly used in desserts, salads, as a complement to meat dishes and infruit cocktail. The popularity of the pineapple is due to its sweet-sour taste containing 15% sugar and malic and citric fruit acids. It is also high in vitamin B1, B2, B6 and C. Its protein-digesting enzyme bromelain seems to help digestion at the end of a high protein meal. In the Philippines, pineapple leaves are used as the source of a textile fiber called piña. The pineapple is a herbaceous short-lived perennial plant which grows to 1.0 to 1.5 metres (3.3 to 4.9 ft) tall. The plant only produces one fruit and then dies. Commercially suckers that appear around the base are cultivated.
It has 30 or more long, narrow, fleshy, trough-shaped leaves with sharp spines along the margins that are 30 to 100 centimetres (1.0 to 3.3 ft) long, surrounding a thick stem. In the first year of growth the axis lengthens and thickens, bearing numerous leaves in close spirals. After 12 to 20 months the stem grows into a spike-like inflorescence up to 15 cm long with over 100 spirally arranged, trimerous flowers, each subtended by a bract. Flower colours vary, depending on variety, from lavender, through light purple to red. The ovaries develop into berries which coalesce into a large, compact, multiple accessory fruit. The fruit of a pineapple is arranged in two interlocking helices, eight in one direction, thirteen in the other, each being a Fibonacci number. (http://en.wikipedia.org/wiki/Pineapple) Saccharification is the process of breaking a complex carbohydrate into its monosaccharide components.
It is the hydrolysis of carbohydrates such as cellulose and starch. It increases hydrolysis rates by reducing product inhibition of enzymes and reduces tank usage by combining the processes into one (http://www.merriam-webster.com/dictionary/saccharification) Phenol Sulfuric Acid Method is an example of a colorimetric method that is widely used to determine the total concentration of carbohydrates present in foods. A clear aqueous solution of carbohydrates to be analyzed is placed in a test tube, then phenol and sulfuric acid are added.The solution turns a yellow- orange color as a result of the interaction between the carbohydrates and phenol.
The sulfuric acid causes all non- reducing sugars to be converted to reducing sugars so that this method determines the total sugar present. This method is non- stoichemetric and so it is necessary to prepare a calibration curve using a series of standard known carbohydrate concentration (http://www.merriam-webster.com/dictionary/phenol-sulfuric acid method). Dilute Acid Hydrolysis is a process of hydrolyzing lignocellulosic materials by subjecting dried lignocellulosic material in a reactor to a catalyst comprised of a dilute solution of a strong acid to lower the activation energy of cellulose hydrolysis and ultimately obtain higher sugar yields (http://www.merriam-webster.com/dictionary/dilute acid hydrolysis).
Statement of the Problem
This study aims to saccharify pineapple Ananas comosus peelings through dilute acid hydrolysis. Specifically, the study attempts:
1. To know whether the dilute acid hydrolysis is an effective way of yielding concentration of sugar from pineapple peelings; 2. To determine whether the temperature has an effect on the concentration of sugar; 3. To determine whether the length of time of reacion can affect the concentration of sugar that will be obtained. Hypothesis:
1. The dilute acid hydrolysis is an effective way of yielding a greater concentration of sugar. 2. The higher the temperature of the solution, the greater the concentration. 3. The longer the time of reaction, the greater the concentration of sugar that will be obtained.
Significance of the study
On average, 435,000 metric tons of pineapples are produced annually in the Philippines, which is one of the country’s leading commercial fruit products. However, there are a lot of unused excess parts of the pineapple, notably the peelings, which are considered as waste and contribute to the country’s garbage problem.
This study aims to utilize pineapple peelings as a substrate for Saccharification process through dilute acid hydrolysis. By means of this, the concentration of sugar present in this biomass can be determined which can be use for other purposes and for other studies such as producing bioethanol or even biofuel.
Scope and Limitation
This study is limited to the use of pineapple Ananas comosus peelings as a substrate for the saccharification process. The peel samples were bought from the market. The experiment was conducted at Chemical Engineering where the chemicals and other laboratory materials were obtained located at University of the Philippines at Los Baños, Laguna from November to December 2010. The study focuses only on the determination of the concentration of sugar present in the pineapple peelings.
Definition of Terms
Absorbance- is defined as the ratio of the radiant flux absorbed by a body to that incident upon it. Glucose- is called as a simple sugar or monosaccharide
Saccharification – the process of breaking a complex carbohydrate (as starch or cellulose) into its monosaccharide components Spectrophotometer- consists of two instruments, namely a spectrometer for producing light of any selected color (wavelength), and a photometer for measuring the intensity of light. Sulfuric acid (H2SO4) – is a clear, colorless, odorless, viscous liquid that is very corrosive. Sugar- is a term for a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose characterized by a sweet flavor. In food, sugar almost exclusively refers to sucrose, which primarily comes from sugar cane and sugar beet. Standard curve- is a quantitative research tool, a method of plotting assay data that is used to determine the concentration of a substance. It can be used in many biological experiments.
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