1,720,963 research outputs found
Chitosan/Alginate Polyelectrolyte Complexes (PECs) for Bioactive Peptide (BAP) Delivery
No full textShort bioactive peptides (BAPs) have gained significant traction given their potential health benefits, particularly, to aid in mitigating hypertension and diabetes. Hence, their potential application as functional food ingredients, supplements, or nutraceuticals, has been recognised, though not yet realised. However, BAPs are highly susceptible to degradation and instability when considering aspects of the product development process, and the most critical concern remains their susceptibility to hydrolysis in the gastrointestinal tract during digestion that compromises their bioaccessibility and bioavailability. One promising strategy to address this limitation is to encapsulate BAPs in a suitable encapsulation vehicle.
Polyelectrolyte complexes (PECs) obtained by electrostatic self-assembly of oppositely charged chitosan (CS) and alginate (ALG) represent a simple to prepare, sustainable and versatile biopolymer platform for bioactive compounds association and oral delivery. CS+ALG PECs protect against acid, salt hydrolysis, and proteases degradation. However, key underpinning factors such as the role of charge ratio (nˉ/n+) that can contribute to the PEC formation, stability and delivery, need further investigation.
This thesis focuses on studying CS+ALG PECs for the gastrointestinal delivery of BAPs derived from fish, with emphasis in understanding the role of the complexation charge ratio (nˉ/n+). The CS (Mw 111 kDa, degree of acetylation 10%) and two distinct ALG (Mw 21 kDa; M/G 1.4, and Mw 8 kDa; M/G 5.1), were selected to prepare PECs at varying (nˉ/n+). Then their biophysical characteristics were investigated using dynamic light scattering (DLS), small angle X-ray scattering (SAXS), and micro-viscosimetry measurements. The selected PECs (based on size/Rh and stability/z-potential) were then loaded with the BAPs, and the encapsulation efficiency was quantified using HPLC-UV
PEMANFAATAN LIMBAH IKAN SEBAGAI SUMBER ALTERNATIF PRODUKSI GELATIN DAN PEPTIDA BIOAKTIF: REVIEW
Full text linkGelatin merupakan polipeptida yang telah diaplikasikan secara luas pada berbagai jenis industri pangan, farmasi, kosmetik dan fotografi. Gelatin juga dapat dihidrolisis menjadi derivat-derivat peptida bioaktif yang berpotensi mencegah dan mengobati berbagai macam penyakit. Namun, gelatin komersial yang berasal dari kulit babi, kulit sapi dan tulang sapi tidak diterima oleh beberapa agama. Sehingga pencarian sumber alternatif untuk produksi gelatin terus dikembangkan 10 tahun belakang ini. Limbah ikan merupakan sumber produksi gelatin yang paling potensial. Oleh karena itu paper ini menyajikan perkembangan pemanfaatan limbah ikan untuk produksi gelatin dan peptida bioktif. Metode pendekatan yang dilakukan yakni dengan studi literature dan review jurnal. Hasil studi menunjukkan bahwa kulit, tulang, kepala, sirip dan sisik ikan bisa digunakan untuk produksi gelatin. Kulit dan tulang ikan merupakan limbah yang paling banyak digunakan untuk produksi gelatin Sebesar 30% dari bagian ikan adalah kulit dan tulang. Ikan yang dimanfaatkan kulit dan tulangnya terdiri dari ikan perairan dingin dan ikan perairan hangat. Gelatin dari kulit dan tulang ikan juga dianalisa kemampuannya sebagai peptida bioaktif, baik tanpa dan dengan hidrolisis terlebih dahulu. Kemampuan peptida bioaktif ini telah terbukti dapat digunakan sebagai antioksidan, antihipertensi, treatment diabetes tipe 2, dan antimikroba. Kata kunci: gelatin, limbah ikan, peptida bioakti
PERSEPSI IBU-IBU PENGURUS POSDAYA TERHADAP KEAMANAN PANGAN JAJANAN ANAK SEKOLAH
Full text linkPERSEPSI IBU-IBU PENGURUS POSDAYA TERHADAP KEAMANAN PANGAN JAJANAN ANAK SEKOLAH Abstrak Penelitian ini dilakukan untuk mengetahui gambaran persepsi ibu-ibu posdaya terhadap keamanan pangan jajanan anak sekolah (PJAS). Pengumpulan data dilakukan dengan penyebaran kuisioner. Sampel penelitian ibu- ibu Posdaya Mawar Setu Kelurahan Setu Kecamatan Cipayung Jakarta. Data yang diperoleh dianalisis deskriptif dan statistik. Uji validitas dan reliabilitas dilakukan terhadap pertanyaan-pertanyaan tertutup. Data yang valid dan reliabel dianalisis dengan tabulasi silang untuk mendapatkan nilai Chi-square. Jika terdapat hubungan antara parameter, dilanjutkan dengan analisis regresi. Hasil analisis menunjukkan bahwa >80% pertanyaan valid. Nilai reliabilitas dari pertanyaan tertutup 0,730. Sebagian besar ibu-ibu posdaya memiliki rentang usia 36-45 tahun (50%), pendidikan terakhir SLTA (55%), pengeluaran 1 juta-2,5 juta (90%) dan merupakan ibu rumah tangga dengan pekerjaan sambilan (80%). Jumlah ibu-ibu posdaya yang mengetahui pengaruh bahan kimia 85% dan 80% mengetahui pengaruh pangan yang tidak higienis, tetapi masih pengetahuan yang sifatnya umum. Sebanyak 70% ibu-ibu posdaya memonitor makanan jajanan anak sekolah dan 85% berasumsi bahwa membawa bekal lebih baik dari pada pangan jajanan. Pengetahuan, kepedulian dan persepsi ibu-ibu posdaya Mawar Setu terhadap pangan jajanan anak sekolah dikategorikan cukup. Nilai Chi-square menunjukkan terdapat hubungan antara parameter pengeluaran dan pekerjaan dengan persepsi ibu-ibu posdaya terhadap pangan jajanan. Nilai R square hubungan profil pengeluaran dan pekerjaan terhadap persepsi berkisar antara 0,024-0,277. Kata Kunci: persepsi, pangan jajanan anak sekolah, posdaya, keamanan pangan, analisis deskriptif. PERCEPTION OF POSDAYA MEMBERS TOWARD SREETFOOD SAFETY OF SCHOOLCHILDREN Abstract In this research determined perception of mother‘s as member of the posdaya toward street food safety of schoolchildren. Data was collected by questionnaire. Sample is mother‘s as member of Posdaya Mawar Setu, Setu villages, Cipayung sub-district, Jakarta. Data were analyzed descriptively and statistically. Validation and reliable analysis was done on closed questions. Valid and reliable data were analyzed with cross tabulation to obtain Chi-square value, and than last analysis is regretion. Result shown that valid question around >80% and reliable value 0,730. Most respondent are 36-45 years old (50%), senior high school educated (55%), spending money Rp 1,000,000-Rp 2,500,00 million per month (90%) and there are house wife with part time job (80%). About 85% mother‘s as member of posdaya know effect of chemicals in food and 85% know about effect of unhygienic food. Unfortunatelly, their knowledge still general. About 70% responden supervise street food of schoolchildren and 85% assume that take lunch to school more efficient compared street food. Knowledge, awareness and perceptions toward street food categorized medium level. Chi-square value indicate that have correlation between parameters of spending money per month and job with perception of mother as member of posdaya toward street food. R square value 0,024-0,277. Keywords: perception, street food schoolchildren, posdaya, food safety, descriptive analysis
Production and Characterization of an Arabinose Isomerase from Gene of Geobacillus stearothermophilus Local Strain
No full textEnzim arabinosa isomerase (AI) dapat mengkatalisis secara revesible reaksi isomerisasi D-galaktosa menjadi D-tagatosa. Tagatosa telah digunakan sebagai pemanis rendah kalori (1,5 kkal/g) yang memiliki tingkat kemanisan 92% dibandingkan sukrosa. Tagatosa memberikan berbagai manfaat kesehatan diantaranya seperti menurunkan berat badan, prebiotik, anti-histolisis serta mereduksi sejumlah gejala yang berhubungan dengan diabetes tipe 2, hiperglikemia, obesitas, anemia dan hemophilia. Peran tagatosa sebagai antidiabetes akan bermanfaat sebagai gula alternatif di Indonesia, mengingat Indonesia menempati peringkat ke-4 dengan jumlah penderita diabetes terbesar di dunia.Arabinose isomerase (AI) is an enzyme that catalyzes isomerization of galactose to tagatose. Besides being used as a low-calorie sweeteners, tagatose has been developed as a functional food because it provides many health benefits such as promoting of weight-loss, anti-halitosis, prebiotic, treating of obesity and reducing in symptoms associated with type 2 diabetes, hyperglycemia, anemia, and hemophilia. Thermostable AIs are potential for tagatose production. AI enzymes encoded by araA gene. The araA gene Geobacillus stearothermophilus originated from Tanjung Api, Poso, Indonesia has been successfully cloned and exspressed at previously study in E. coli BL21 (DE3) pLysS. However expression level of AI still low by SDS-PAGE analysis. The E. coli BL21 was incubated in 37°C at 150 rpm. This research was conducted to optimize the araA gene expression. Result from this research showed that the medium tofu liquid waste consisting yeast extract 0.5% (TLW+YE) increased enzyme productivity. Optimation production was obtained by 16 hours induction. The purification was carried out with three steps of freeze-thaw at -70°C, heat treatment (60°C, 30 minutes) and DEAE ion exchange chromatography (elution buffer 0-1000 mM NaCl). The purified enzyme exhibited optimum activity at 60°C and pH 7. The AI activity in the presence of CaCl2 and MnCl2 was increased to 152% and 563% respectively. Heat stability of enzymes in the presence of CaCl2 and MnCl2 was increased. Half-life (t 1/2) AI in the presence 1 mM of CaCl2 and MnCl2 was increased becomes 301 and 990 minutes respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
IDENTIFIKASI GELATIN DARI TULANG IKAN PATIN HASIL EKSTRAKSI MENGGUNAKAN KULIT NANAS DENGAN ELEKTROFORESIS VERTIKAL
Full text linkTulang ikan merupakan sumber alternatif yang paling potensial untuk produksi gelatin. Upaya pencarian gelatin dari berbagai jenis tulang ikan juga dilakukan melalui serangkaian penelitian di Indonesia. Namun, keberhasilan hasil ekstraksi hanya diukur dengan kadar protein kasar atau rendemen. Padahal identifikasi keberhasilan ekstraksi dapat dilakukan dengan metode yang lebih akurat. Penelitian ini dilakukan untuk mengindentifikasi gelatin tulang ikan patin hasil ekstraksi dalam cairan kulit nanas dengan metode elektroforesis vertikal. Tahapan ekstraksi gelatin dilakukan dengan pre-treatment tulang ikan patin dalam ekstrak kulit nanas selama 21-27 jam. Ekstraksi utama dalam air dilakukan 5 jam pada suhu 65-75 oC. Identifikasi keberadaan gelatin hasil ekstraksi dilakukan dengan metode sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Penetapan keberhasilan hasil ekstraksi dengan metode SDS-PAGE dilakukan dengan bantuan protein penanda (marker) dan perbandingan terhadap penelitian-penelitian terdahulu. Hasil penelitian menunjukkan bahwa gelatin tulang ikan patin yang diekstrak dengan kulit nanas teridentifikasi dalam gel poliakrilamid pada kisaran berat molekul ~120 kDa (jenis alfa gelatin). Berat molekul ini sesuai dengan penelitian ekstraksi tulang ikan patin menggunakan asam klorida dan ekstraksi tulang ikan beloso. Berdasarkan identifikasi dengan SDS-PAGE diketahui bahwa pita yang lebih nyata dan cukup tebal antar perlakuan terdapat pada perlakuan pre-treatment 27 jam dan ekstraksi utama 5 jam suhu 75 oC.
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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