Search

Highlight Research • The homogenization process affected the particle size reduction • The homogenization process using both High Speed Homogenizer and Ultrasound had a smaller particle size and the highest efficiency in encapsulation Abstract Arthrospira platensis contains a high concentration of carotenoids mainly 80 % β-carotene. The use of β-carotene in functional food and nutritional supplements was constrained by its lack of chemical and physical stability. Therefore, efforts were needed to protect carotenoids from damage by using an encapsulation system. The emulsion preparation before the encapsulation process had an influence on the stability of the oil-in-water emulsion. Various methods were used to prepare emulsions, such as high shear homogenizers (HSH) and ultrasound (US) treatment. The homogenization step was critical because it influenced the chemical stability of any encapsulated compounds. The purpose of this work was to generate nanocapsules of β-carotene with minimum carotenoid degradation, high efficiency of encapsulation, and small particle size, with variation in the homogenization process. This study consisted of 5 treatments, including the homogenization processes used HSH 24.000 rpm for 90 s ; HSH 24.000 rpm for 60 s, amplitude 55 % for 120 s ; amplitude 94 % for 138 s ; amplitude 55 % for 138 s ; and amplitude 55 % for 120 s . Each parameter was analysed by ANOVA followed by Tukey pairwise comparisons with 95% confidence level and p

One of an important quality parameter in tuna is the level of histamine content. The contamination of histamine in tuna is mainly due to the activity of histidine decarboxylase produced by the bacteria. A rapid growth of histamine producing bacteria is correlated with the practice of temperature abuse during handling. This study aimed to develop predictive growth modeling of two histamine-producing bacteria in the function of temperature. The growth and histamine production of Klebsiella sp. CK02 and Morganella morganii ATCC 25830 at various temperatures were measured in tryptic soy broth histidine (TSBH) and tuna fish infusion broth (TFIB) growth media. Broths were incubated at 4°C and 15°C for 7 days, and at 30°C and 40°C for 24 hours. The Baranyi and Roberts model was used with DMFit to determine primary growth kinectics, and the Ratkowsky square root model to describe bacterial growth rate as a function of temperature. Histamine production was enumerated by the apparent yield factor (pYhis/CFU) value. Growth rate increased with temperature, with a maximum rate at 40°C for Klebsiella sp. CK02 (0.740 log CFU/h) and M. morganii (0.578 log CFU/h). The Tmin for Klebsiella sp. CK02 in TFIB was -8.9°C, indicating better survival in low storage temperature, compare to M. morganii ATCC 25830. In addition, Klebsiella sp. CK02 produced a lower pYhis/CFU at 15 and 30°C compared to M. morganii ATCC 25830.

Spirulina is a microalgae, easily cultivated and grows well in a low to high-level of salinity. Chemical contents in Spirulina can be influenced by the conditions of cultivation. Spirulina platensis sold in Indonesia is largerly cultured in marine water or fresh water medium. S. platensis can be used as a source of calcium because it has 700-1000 mg/100 g of dry biomass. This study aimed to determine the effect of sea water and fresh water cultivation medium on the chemical composition of S. platensis. Samples were determined the chemical composition included proximate analysis, mineral content of Calcium (Ca), Magnesium (Mg) and Phosphor (P), total glucose, starch, and dietary fiber. Functional properties were also determined i.e: solubility, water and oil binding capacities, emulsion and foam abilities. The results showed that the content of ash and minerals (Ca, Mg, P) of S. platensis cultivated in marine water was higher that of S. platensis cultivated in freshwater. This results suggested that S. platensis cultured in the sea water medium was potential as an alternative source of calcium (512,53 mg Ca/100 g) with a ratio Ca-P = 1:1.79. The carbohydrate content was at least 28,41 %db (total sugars almost 0,09 %db, starch 6,9 %db and total dietary fiber 24,81 %db). The dietary fiber was dominated by insoluble dietary fiber (24,81 %db). Functional properties were affected by cultured medium. Spirulina platensis cultivated in marine water exhibited high capacity on Water and Oil Holding Capacities (WHC and OHC) that were 4,46 ml/g and 2,35 ml/g, respectively. Water Solubility Index (WSI), foaming capacity, emulsion capacity were not affected by cultured media. ABSTRAK Spirulina merupakan mikroalga, mudah dibudidayakan dan dapat hidup dalam tingkat salinitas yang rendah hingga tinggi. Kandungan kimia dalam Spirulina dapat dipengaruhi oleh media budidayanya. Di Indonesia Spirulina platensis yang beredar sebagian merupakan hasil budidaya dari berbagai tempat dengan media budidaya air tawar maupun air laut. S. platensis dapat digunakan sebagai salah satu sumber kalsium karena kandungannya dapat mencapai 700-1000 mg/100 g biomassa kering. Penelitian ini bertujuan untuk mengetahui pengaruh media budidaya air laut dan air tawar terhadap komposisi kimia dan sifat fungsional dari S. platensis. Parameter kimia yang diamati yaitu komposisi proksimat, kandungan mineral Ca, Mg dan P, kandungan gula, pati dan serat pangan. Parameter sifat fungsional meliputi kelarutan, kemampuan mengikat air dan lemak, emulsifikasi dan kemampuan membentuk busa. Hasil penelitian menunjukkan bahwa kandungan abu dan mineral (Ca, Mg, P) S. platensis budidaya air laut lebih tinggi daripada budidaya air tawar. S. platensis asal budidaya laut berpotensi sebagai alternatif sumber kalsium (512,53 mg Ca/100 g) dengan rasio Ca:P = 1:1,79. Kandungan karbohidrat S. platensis hasil budidaya media air laut lebih rendah yaitu 28,41 %db (gula total dengan nilai 0,09 %db, pati 6,9 %db dan total serat pangan 24,81 %db), serat pangan terutama berupa serat pangan tak larut sebesar 24,18 %db. Sifat fungsional dipengaruhi oleh asal budidaya. Spirulina platensis asal budidaya laut memiliki sifat Water Holding Capacity (WHC) yang lebih tinggi yaitu 4,46 ml/g dibandingkan sifat Oil Holding Capacity (OHC) yaitu 2,35 ml/g, sedangkan Water Soluble Index (WSI), kapasitas membentuk busa dan emulsifikasi tidak dipengaruhi media budidaya.

Kulit ikan nila hitam (Oreochromis niloticus) dapat diekstraksi menjadi kolagen dan turunannya sebagai salah alternatif peningkatan nilai tambah limbah industri perikanan. Ekstraksi kolagen dari sampel kulit ikan nila hitam menggunakan asam asetat (metode asam) dan dipresipitasi dengan larutan garam dapur (NaCl) 0,9 M. Untuk meningkatkan optimasi isolasi kolagen (berdasarkan jumlah rendemen), kulit ikan nila hitam diekstraksi dengan 3 perlakuan konsentrasi asam asetat, masing-masing: 0,25 M; 0,50 M; dan 0,75 M pada selang waktu 16 dan 48 jam. Dari hasil pengujian diketahui bahwa perlakuan interaksi konsentrasi asam asetat dan waktu ekstraksi tidak berpengaruh nyata (p>0,05) terhadap pembentukan rendemen kolagen pada tingkat signifikansi 95%. Perlakuan asam asetat 0,75 M pada selang waktu 16 jam menghasilkan rendemen terbesar (5,96%), dengan suhu denaturasi kolagen mencapai 35,75 oC; serta komposisi asam amino: glisin 5395,82 ppm (52,99%), alanin 2979,15 ppm (22,08%), dan asam glutamat 1684,42 ppm (7,45%). Berdasarkan analisis SDS-PAGE, diketahui bahwa kolagen dari sampel kulit ikan nila hitam mengandung ikatan rantai- dan rantai- sebagai kolagen tipe-I.

Background: Limited data exist from southeast Asia on the impact of SARS-CoV-2 variants and inactivated vaccines on disease severity and death among patients hospitalised with COVID-19., Methods: A multicentre hospital-based prospective cohort was enrolled from September 2020 through January 2023, spanning pre-delta, delta, and omicron periods. The participant hospitals were conveniently sampled based on existing collaborations, site willingness and available study resources, and included six urban and two rural general hospitals from East Nusa Tenggara, Jakarta, and North Sumatra provinces. Factors associated with severe disease and day-28 mortality were examined using logistic and Cox regression., Findings: Among 822 participants, the age-adjusted percentage of severe disease was 26.8% (95% CI 22.7-30.9) for pre-delta, 50.1% (44.0-56.2) for delta, and 15.2% (9.7-20.7) for omicron. The odds of severe disease were 64% (18-84%) lower for omicron than delta (p < 0.001). One or more vaccine doses reduced the odds of severe disease by 89% (65-97%) for delta and 98% (91-100%) for omicron. Age-adjusted mortality was 11.9% (8.8-15.0) for pre-delta, 24.4% (18.8-29.9) for delta and 9.6% (5.2-14.0) for omicron. The day-28 cumulative incidence of death was lower for omicron (9.2% [5.6-13.9%]) than delta (28.6% [22.0-35.5%]) (p < 0.001). Severe disease on admission was the predominant prognostic factor for death (aHR34.0 [16.6-69.9] vs mild-or-moderate; p < 0.001). After controlling for disease severity on admission as an intermediate, the risk of death was 48% (32-60%) lower for omicron than delta (p < 0.001); and 51% (38-61%; p < 0.001) lower for vaccinated participants than unvaccinated participants overall, and 56% (37-69%; p < 0.001) for omicron, 46% (-5 to 73%; p = 0.070) for pre-delta (not estimable for delta)., Interpretation: Infections by omicron variant resulted in less severe and fatal outcomes than delta in hospitalised patients in Indonesia. However, older, and unvaccinated individuals remained at greater risk of adverse outcomes., Funding: University of Oxford and Wellcome Trust., Competing Interests: The studies included in this analysis received funding from the COVID-19 Research Response Fund of the University of Oxford (0009109 and 0009308); Wellcome Africa Asia Programme Vietnam (106680/Z/14/Z); Wellcome Trust (222574/Z/21/Z). JKB, AHS and RLH are supported by the Wellcome Africa Asia Programme Vietnam (106680/Z/14/Z). We declare no other competing interests., (© 2023 Published by Elsevier Ltd.)