nan Hadiyanto

Synthesis and characterization of ZnO:TiO2 nano composites thin films deposited on glass substrate by sol-gel spray coating technique

In this work, (ZnO)x:(TiO2)1-x nano composites thin films, with x = 1, 0.75, 0.5, 0.25, and 0, have been prepared by sol–gel spray coating technique onto glass substrate. Pure TiO2 and ZnO thin films were synthesized from titanium isopropoxide-based and zinc acetate-based precursor solutions, respectively, whereas the composite films were obtained from the mixture of these solutions at the specific % vol ratios. The properties and performance of nano composite ZnO, TiO2 and ZnO:TiO2 thin films at different composition have been investigated. Ultraviolet – Visible (UV-Vis) Spectrophotometer and Scanning Electron Microscopy (SEM) were employed in order to get morphology and transmittance of thin films. Testing the ability of photocatalytic activity of obtained films was conducted on photodegradation of methylene blue (MB) dye and organic pollutants of wastewater under a 30 watt UV light irradiation, then testing BOD, COD and TPC were conducted. Using the Tauc model, the band-gap energy decreased from 3.12 e...

Encapsulation of phycocyanin-alginate for high stability and antioxidant activity

The aim of this study was to obtain optimal condition of phycocyanin-alginate encapsulation, encapsulation efficiency and phycocyanin load, physicochemical properties of beads, in vitro release study, stability and antioxidant activity. The result product with alginate content 1,5% (w/v) and 2% (w/v) produced were in spherical shape than product with alginate content 2,5% (w/v) by ratio of phycocyanin 1:1. Increasing alginate content on encapsulation process will increase of encapsulation efficiency and phycocyanin load. In vitro released study showed that phycocyanin-alginate beads were more resistant in simulated gastric fluid, while rapidly release in simulated intestinal fluid. The antioxidant activity showed that phycocyanin antioxidant activity decreased after encapsulation process due to duration of storage and the possibility of a cracking which will cause reduced stability of phycocyanin.

Study on the effect of different concentration of Spirulina platensis paste added into dried noodle to its quality characteristics

High nutritional content of microalgae S. platensis is very good for human health especially for its protein and β-carotene. These compounds can be used for improving quality of food from nutritional point of view. This study was designed to observe the effect of different concentration of S. platensis paste to dried noodle quality based on physical, chemical and sensory perspectives. Material used in this study was S. platensis powder obtained from CV Neoalgae, Sukoharjo. The best treatment observed from preliminary study was then used for further study and compared to control treatment (without added S. platensis paste). The dried noodle resulted was then analyzed for elasticity, chemical (β-carotene, water, protein, ash, fat and carbohydrate) and sensory (hedonic). Parametric data obtained were analyzed using t-Test while non-parametric data was analyzed using Kruskal-Wallis followed by Multiple Comparison test. The study showed that dried noodle added with 9% S. platensis paste give significant effect (P<0.05) on elasticity; β-carotene, water, protein, ash, fat and carbohydrate and also sensory (hedonic). Dried noodle without added S. platensis paste has lower in β-carotene and protein compared to that of added S. platensis paste with the value of 0.06 mg/100 gr and 17.51 mg/100gr (β-carotene) and 8.88% and 38.6% (protein), respectively. Those, chemical composition of dried noodle added with S. platensis comply with Indonesian National Standard in term of protein, water, and ash content with sensory of 7.26 ≤ μ ≤ 7.63. Addition of S. platensis can significantly increase the nutritional of dried noodle especially protein (by 4 times) and β-carotene.

The effects of temperature and frequencies in ultrasound assisted extraction of phycocyanin from microalgae Spirulina sp

Microalgae Spirulina sp has been identified as source of protein and other high added value compounds. One of the compounds is phycocyanin as also known for antioxidant use. The extraction of this compound by using conventional method (soxhlet extraction) resulted low yield and longer processing time. This research was aimed to extract phycocyanin by using an extraction assisted by ultrasound irradiation. The extraction was performed by using variable of ultrasound frequency and extraction temperature and ethanol was used as a solvent. The result showed that yield of phycocyanin extracted by conventional method was 11.13% while the ultrasound irradiation could increase the yield up to 15.61% at constant frequency of 42 kHz, while the optimum temperature was obtained at 45°C. The analysis of variable interactions showed that both temperature and time has an interaction and temperature was the highest variable in increasing the yield. The conclusion of this research was the ultrasound could improve significantly the efficiency of extraction as well as activity of phycocyanin extracted from microalgae.

Effect of Melanin Free Ink Extracted From Squid (Loligo sp.) on Proximate and Sensory Characteristics of Soft-Bone Milkfish (Chanos chanos) During Storage

Antioxidant could be extracted and isolated from squid inks. Squid ink in the form of melanin free ink (MFI) could be act as an electron donor which can stabilize free radicals in lipid oxidation. This study was carried out to assess the antioxidant activity of squid inks converted into MFI in different dilution and to optimize the extraction conditions for the application of MFI as an antioxidative agent on fish product. Three different types of MFI extracts i.e : pure squid ink, squid ink with 5 times dilution and squid ink with 10 times dilutions by using cooled ionized water (4°C). The ink was then centrifuged at 18.000 x g for 30 minutes at cooled centrifuge (4°C) followed by DPPH analysis. The results showed that the IC50 of MFI extracts were 2.84 ppm; 1.11 ppm and 0.34 ppm, respectively (p < 0.05). The results indicated that squid ink with 10 times dilution in extraction of MFI had the highest value in free radical inhibitory. Although the IC50 of three different dilutions are equally low, and are considered as very strong antioxidative agent, however, it showed that the MFI extracted from squid ink had the ability to prevent free radical

Improvement of Stability and Antioxidant Activities by Using Phycocyanin - Chitosan Encapsulation Technique

Encapsulation is a coating process to improve the stability of bioactive compounds. Phycocyanin with high antioxidant activity has been encapsulated with chitosan in microcapsules form. In this study aims to determine the best conditions in the encapsulation process using the extrusion method, characterization of the physicochemical properties of the microcapsules, antioxidant activity test using DPPH, in vitro release performance and evaluate the storage stability against temperature. The results of the encapsulation process is obtained: Na-TPP is better than Na-citrate as crosslinker and chitosan content 3% as a coating with ratio of chitosan to phycocyanin ratio 1: 1. Test of antioxidant activity also showed encapsulation with chitosan content 3% has the highest antioxidant activity. Morphological analysis microcapsules were found to have compact spherical shape with diameter range 900-1000 µm. In vitro release testing showed a quick release in an acidic environment (SGF) for 2 hours and slowly release under alkaline conditions (SIF) for 8 hours under mechanical stirring at 37°C. Phycocyanin much more stable against temperature during storage in microcapsules.