The Drying Rate of Chlorella pyrenoidosa Using an Oven in Bioethanol Production

The production of bioethanol from microalgae goes through several stages, including cultivation, harvesting, drying, storage, and conversion to bioethanol. Nearly 40% of the total energy consumed in the bioethanol production from microalgae is from drying. This research aims to study the drying rate model of Chlorella pyrenoidosa using an oven. The drying is carried out at the temperatures of 50, 60, and 70 oC. The initial moisture content of Chlorella pyrenoidosa was 317.798% dry weight. The results showed that at the temperatures of 50, 60, and 70 oC, the critical moisture content was 9.108, 7.583, and 6.93% dry weight, while the equilibrium moisture content was 3.172, 3.158, and 3.109% dry weight. The most optimal drying is at 70 oC and the drying rate gets faster as the temperature does too. The Page model is better at describing the drying rate of Chlorella pyrenoidosa using an oven than the Newton model. The drying speed constants (k) were 0.00056, 0.00061, and 0.00208, at 50, 60, and 70 oC, respectively.

Understanding wet tear strength at varying moisture content in handsheets

A laboratory study was conducted looking at the effects of moisture content on wet tear strength in handsheets. Three different wetting techniques were used to generate the wet tear (Elmendorf-type) data at varying moisture levels, from TAPPI standard conditions (dry) to over 60% moisture content (saturated). Unbleached hard-wood and softwood fiber from full-scale kraft pulp production were used. The softwood fiber was refined using a Valley beater to reduce freeness. Handsheets were made with a blend of hardwood and softwood and with refined softwood, without the addition of wet-end chemistry. The resulting grams-force tear data obtained from the test was indexed with basis weight and plotted versus both moisture content and dryness. As moisture content levels in the handsheets increased, the wet tear strength also increased, reaching a critical maximum point. This marked a transition point on the graph where, beyond a critical moisture content level, the tear strength began to decline linearly as moisture increased. This pattern was repeated in handsheets made from a blend of hardwood and softwood and from 100% refined softwood.

PENDUGAAN UMUR SIMPAN MAKANAN TRADISIONAL BERBAHAN DASAR BERAS DENGAN METODE ACCELERATED SHELF-LIFE TESTING (ASLT) MELALUI PENDEKATAN ARRHENIUS DAN KADAR AIR KRITIS

The expired date is important information that consumers should know. However, many traditional foods have not written an expiration due date. The purpose of this study was to estimate the shelf life of two (2) types of traditional rice-based foods intip and kembang goyang. Estimation of shelf life was carried out using the Accelerated Shelf-life Testing (ASLT) method using the Arrhenius approach and the critical moisture content approach. The calculation of shelf life in the Arrhenius approach to kembang goyang has been obtained respectively 0.45 months, 0.50 months, and 0.47 months at respective temperatures (25oC, 35oC and 45oC). The results of shelf life kembang goyang through the water content approach obtained 0.43 months at 75% RH. The results of the arrhenius approach to intip showed that shelf life of 0.37 months, 0.45 months, and 0.53 months at each temperature (25oC, 35oC, and 45oC). The critical water content approach for intip has obtained a shelf life of 0.58 months (RH 75%). Intip has a slightly larger shelf life when analyzed using the critical moisture content method. Keywords: ASLT, intip, kembang goyang, shelf life

Pendugaan Umur Simpan Tiwul Instan yang Dikemas dalam Aluminium Foil dan Polietilen dengan Metode Akselerasi Berdasarkan Pendekatan Kadar Air Kritis

Penelitian bertujuan untuk menentukan umur simpan tiwul instan tinggi protein yang dibuat dari tepung ubi kayu dengan perlakuan modifikasi mikrobiawi dan kimiawi yang dikemas dalam kemasan aluminium foil dan plastik polietilen yang dihitung menggunakan metode akselerasi berdasarkan pendekatan kadar air kritis. Penelitian ini menggunakan metode eksperimental. Modifikasi mikrobiawi dilakukan dengan memfermentasi ubi kayu dengan ragi tape 4% dan diinkubasi selama 6 jam, sedangkan perlakuan kimiawi adalah dengan cara merendam ubi kayu dalam larutan soda kue selama 15 menit. Tiwul instan selanjutnya dibungkus dalam kemasan aluminium foil dan kemasan plastik polietilen. Kadar air tiwul dan tekstur dianalisis selama penyimpanan. Pembuatan pola kurva isotherm sorpsi air dan penghitungan masa simpan produk juga dilakukan pada penelitian ini. Hasilnya, tiwul instan perlakuan modifikasi kimiawi pada ubi kayu mempunyai masa simpan sekitar dua kali lipat dari perlakuan modifikasi mikrobiawi, yaitu masing-masing selama 4,88 tahun dan 2,13 tahun (yang disimpan dalam polietilen) serta 8,55 dan 3,89 tahun (yang disimpan dalam aluminium foil). Kesimpulannya, pendekatan titik air kritis dapat dilakukan untuk mendeteksi masa simpan tiwul instan, baik yang dikemas dalam aluminium foil maupun kemasan polietilen yang dapat menghasilkan masa simpan tiwul instan.“High Protein Instant Tiwul” Shelf Life Packed with Aluminum Foil and Polyethylene Using Critical Moisture Content ApproachAbstractThe research aims to determine the shelf life of high protein instant tiwul made from cassava flour with chemical and microbial modification packed in aluminum foil and polyethylene plastic packaging using the acceleration method with the critical moisture content approach. Fermented cassava (at 4% concentration for 6 hours incubation) was used as microbial modification treatment while cassava immersed in baking soda solution for 15 minutes was also applied as chemical modification. Instant tiwul was then packaged using aluminum foil and polyethylene. Moisture content of instant tiwul was determined during storage while water sorption isotherm curve patterns was also generated. Instant tiwul of cassava with chemical modified treatment had twice in shelf life, longer than those of microbial modification treatment, resulting 4.88 and 2.13 years (using polyethylene package) while 8.55 and 3.89 years (using aluminum foil), respectively. As conclusion, critical moisture approach could be used in the detection of shelf life in instant tiwul with polyethylene and aluminum foil packaging.

Study of the forms of moisture bond in coriander seeds based on analysis of drying kinetics

The article deals with the issues related to the study of the forms of connection of moisture removed during the drying of coriander seeds. A study was carried out to determine the quantitative moisture content of various forms of communication by two methods and a comparative analysis was carried out. It is shown that the existing methods for studying the forms of moisture-material bond have significant drawbacks and generally give a qualitative assessment of the state of moisture in the material or are very laborious and require lengthy laboratory research. An approach is proposed to determine the forms of moisture bond in coriander seeds based on graph-analytical analysis of the drying kinetics, which makes it possible to qualitatively and quantitatively assess the state of moisture in the seeds. With the help of a graphical editor, the curves of the kinetics of drying of coriander seeds were processed and the dependences of the value characterizing the rate of change in the rate of drying of coriander seeds on the moisture content of the product were obtained, and the introduction of a new concept into the theory of drying of this value as "acceleration of drying" was proposed. The analysis of the obtained curves is carried out, indicating the presence of extrema and points of inflection to the corresponding critical moisture content, as well as the presence of areas with a slowdown or acceleration of the drying rate change, which make it possible to establish the intervals of moisture removal with different binding energies. The approach considered in the article to determine the forms of moisture bond in coriander seeds will allow not only to give a qualitative and quantitative assessment of the state of moisture in products, but also to reduce the time spent on analysis and increase the accuracy of the results.

Development of jackfruit leather and its shelf-life analysis in different packaging materials

Post-harvest loss is very common in seasonal fruits due to its high perishability even under refrigerated conditions. Value addition and processing is the best solution to overcome this problem and it also ensures the availability of the product round the year. This study is to develop jackfruit leather that replicates the natural fruit taste and is shelf stable at room temperature (28 ± 2°C). The product contributes 3.63Kcal/g to the energy requirement and is rich in minerals like potassium and sodium (7442μg/g and 1842μg/g, respectively). Sorption isotherm studies showed a sigmoid characteristic for the product. It has a critical moisture content of 48.39±0.44% with respect to 96% relative humidity and a water activity of 0.47. The product was packed in different packaging materials like 220-gauge polyethylene laminated with 50-gauge metalized polyester (Met PE) and 150 gauge Biaxially Oriented Poly Propylene (BOPP) laminated with 50-gauge polyester to study and compare its shelf-life in both the packaging materials at room temperature (28 ± 2°C). Physical and chemical parameters of the product was analyzed during the period of storage and the results revealed a shelf stability for 90 days for the product packed in both the packaging materials.