Determination of the Shelf Life of Microencapsulated Extract of Microalgae NannochloropsisSp with Accelerated Shelf Life Testing Method

• Published in: Annals of the Romanian society for cell biology Vol. 25; no. 5; pp. 2323 - 2331
• Main Authors: Anggreni, A A Made Dewi, Antara, N Semadi, Wrasiati, L P, Gunam, I B W
• Format: Journal Article
• Language: English
• Published: Arad "Vasile Goldis" Western University Arad, Romania 01.01.2021
• Subjects: Algae; Aluminum; Aquatic microorganisms; Equilibrium; Food products; Humidity; Low density polyethylenes; Microcapsules; Moisture content; Packaging; Polyethylene; Shelf life; Sorption; Vapor pressure; Water activity; Water content
• ISSN: 2067-3019; 2067-8282

There are two approaches to be able to estimate the shelf life of a product with the acceleration method, namely: 1) semi-empirical approach with the help of the Arrhenius equation, namely the kinetics theory which generally uses zero or one order for food products, and 2) the critical water content approach withdiffusion theory using changes in moisture content and water activity as expiry criteria. Research Implementation Determination of the shelf life is determined through 2 stages, namely analysis of moisture sorption isothermic characteristics (MSI) and analysis of shelf lifeestimation. 1)Analysis of Moisture Sorption Isothermic Characteristics MSI analysis was carried out by static gravimetric method by storing the sample at ERH 30 - 90%which was conditioned using a saturated salt solution in a chamber at a temperature of 28 ± 2 °C to obtain the product equilibrium moisture content at various aw.Making the ISA curve through several stages, namely: preparation of a saturated salt solution, storage and weighing of the sample, making the water sorption isothermic curve, analyzing the the water sorption isothermiccharacteristics of the sample in the Henderson approach model (Fitriani, 2015). The storage and weighing of the microcapsule samples were carried out as follows: 2 g of the sample with 3 replications for each chamber of the saturated salt solution.The sample was then put into the chamber and stored at a temperature of 28 ± 2 °C.Samples are weighed every day until they reach a balanced weight using digital scales.Before and during weighing, the sample is transferred from the chamber into the desiccator to balance the sample with a controlled atmosphere.The balanced weight is indicated by the difference between 3 consecutive weights of not more than 2 mg/g for samples stored at RH below 90% and no more than 10 mg/g for samples stored at RH above 90% (Adawiyah, 2006; Sukada et al., 2019; Miwada et al., 2018).The sample moisture content was calculated using the oven-drymethod (AOAC, 1995) and expressed on a dry basis.The moisture content in this condition is the equilibrium water content in the ERH used.The resulting data is used to construct a water sorption isothermic curve. Package cross-sectional area (m2) Ws : Microcapsule weight in the package (g) Po : Saturated vapor pressure (mmHg) b : slope of the isothermic sorption curve Determination of the shelf life is carried out in the following manner: the microcapsules are weighed 2 g each, then put into aluminum foil packaging with a thickness of 0.1 mm.The dimensions of the packaging are 5 cm long and 4 cm wide.The product is stored in a storage room with a temperature of 28 °C and RH 75%.The tests that need to be done to determine the shelf life of the microencapsulated - extractof microalgae Nannochloropsis sp.using the Labuza equation is: a.Product Equilibrium Moisture Content (me) The product equilibrium moisture content was determined at room temperature conditions of 28°C and room RH of 75%. b.Initial Moisture Content (mi) The initial moisture content was determined as follows: 2 g of the sample was put into a plate with a known weight, then put in an oven at 105°C.After 3 hours, the plate containing the sample was removed from the oven, cooled in a