Cheese contamination has hit the headlines in recent weeks after Austrian authorities linked seven listerioisis deaths to Prolactal cheese. In light of this news, food safety expert Dr. Eleftherios H. Drosinos explains how risk of contamination from Listeria monocytogenes can

melaluiPlant design and personal hygiene crucial to reducing listeria risk.

By Stephen Daniells, 01-Mar-2010

Related topics: Science & Nutrition, Fats & oils, Flavors and colors

A common surfactant ingredient may boost the stability of citral, one of the most important flavour compounds in citrus oil, and enhance formulations of beverage concentrates, says a new study.

Despite widespread use of citral in foods and beverages, the compound is known to degrade over time under acidic conditions, resulting in a loss of desirable flavours and formation of undesirable off-flavours.

The compound Tween 80 is already used by the food industry as a surfactant – an ingredient that improves oil-in-water emulsion stability by lowering the surface tension of at the interface between oil and water. By incorporating Tween 80 into oil-in-water emulsions it was possible to alter the stability of citral to chemical degradation, say scientists from the University of Massachusetts and flavour giant International Flavors and Fragrances (IFF) in Food Chemistry.

Approaching the same problem from a different angle, the researchers report that use of the non-ionic surfactant PGPR (polyglycerol polyricinoleate) produced so-called reverse micelles in the emulsion, and these too could protect against citral degradation in a beverage formulation.

Despite the positive results, questions remain about the applicability of the development for finished beverage emulsions: The levels of surfactants needed to achieve the results were relatively high, said the researchers, “and may be unsuitable for commercial applications due to cost, taste or regulatory reasons”.

“Future studies should examine the impact of other food grade water-soluble and oil-soluble surfactants on citral degradation in emulsions to minimize its degradation, since it may be possible to utilize lower levels than those used in this study to prevent degradation,” wrote the researchers, led by David Julian McClements from U of M.

Formulation details

The researchers produced micelles and reverse micelles in oil-in-water emulsions. As the concentration of Tween 80 (Sigma Chemical) increased from 1 to 5 per cent, the degradation of citral decreased. This result suggested that incorporation int micelles protected the citral from degradation, said the researchers.

The presence of reverse micelles produced using PGPR (Palsgaard) also increased the stability of citral, with the researchers noting a decrease in “the percentage of citral present within the aqueous phase of the emulsions, suggesting that citral was preferentially incorporated into the reverse micelles”.

“These results show that either micelles or reverse micelles may be used to improve the chemical stability of citral in beverage emulsions,” concluded the researchers.

Source: Food Chemistry
Published online ahead of print, doi: 10.1016/j.foodchem.2010.02.025
“Inhibition of citral degradation in model beverage emulsions using micelles and reverse micelles”
Authors: S.J. Choi, E.A. Decker, L. Henson, L.M. Popplewell, D.J. McClements

Yth. Bapak/Ibu
Di
Tempat

Kami dari panitia Seminar Nasional Rekayasa Kimia dan Proses 2010 Jurusan
Teknik Kimia Universitas Diponegoro mengundang Bapk/Ibu sekalian untuk
berpartisipasi dalam acara SRKP 2010 yang akan diselenggarakan pada:

Hari / Tanggal : Rabu-Kamis / 4-5 Agutsus 2010
Lokasi : Kampus Teknik Kimia Universitas Dipoengoro

Seminar Nasional Rekayasa Kimia dan Proses 2010 merupakan kegiatan tahunan
dan untuk tahun ini bertepatan dengan Lustrum ke-9 Jurusan Teknik Kimia
UNDIP.Seminar ini dibagi dalam beberapa bidang diantaranya: Teknik rekasi Kimia, Food Technology, Teknik Separasi, Process control, Bioprocess engineering, Mass dan heat trasnfer

Batas pengiriman abstrak : 30 Mei 2010
Pemberitahuan abstrak yang diterima : 15 Juni 2010
Penerimaan artikel lengkap : 15 Juli
2010
Untuk submission dapat menggunakan email :
Srkp2010undip@gmail.com

Kami sangat mengharapkan agar informasi seminar ini dapat disebarluaskan
kepada rekan kerja atau teman yang berminat berpartisipasi dalam seminar
ini.

Terlampir kami sertakan brosur kegiatan seminar ini.

Demikian undangan ini kami sampaikan kepada Bapak/Ibu sekalian dan terima
kasih banyak atas perhatian dan kerjasamanya.

Hormat kami,

Dr. Hadiyanto,MSc

(Ketua Panitia)

Achmad Subagyo

Fakultas Teknologi Pertanian Universitas Jember

Kata Mocaf (atau Mocal) adalah singkatan dari Modified Cassava Flour yang berartitepung singkong yang dimodifikasi. Secara definitif, Mocaf merupakan produk tepung dari singkong (Manihot esculenta) yang diproses menggunakan prinsip memodifikasi sel singkong secara fermentasi dengan mikrobia bakteri asam laktat (BAL) mendominasi selama fementasi tepung singkong ini. Mikrobia yang tumbuh menghasilkan  enzim pektolitik dan selulolitik yang dapat mengahncurkan dinding sel singkong sedemikian rupa sehingga terjadi liberasi granula pati.

Mikrobia tersebut juga menghasilkan enzim-enzim yang menghidrolisis pati menjadi gula dan selanjutnya mengubahnya menjadi asam-asam organik terutama asam laktat. Hal ini akan menyebabkan perubahan karakteristik daritepung yang dihasilkan berupa naiknya viskositas, kemampuan gelasi, daya rehidrasi, dan kemudahan melarut. Demikian pula citaras MOCAF menjadi netral dengan menutupi citarasa singkong sampai 70%

untuk artikel lanjutnya dapat dibaca di Foodreview Indonesia edisi Agustus 2008. atau hubungi penulis/penerbit mana yang lebih mudah. semoga membawa manfaat.

Akbarningrum Fatmawati, Rudy Agustriyanto, and Lindawati

World Academy of Science, Engineering and Technology 57 2009

Abstract—

Gluconic acid is one of interesting chemical products in industries such as detergents, leather, photographic, textile, and especially in food and pharmaceutical industries. Fermentation is an advantageous process to produce gluconic acid. Mathematical modeling is important in the design and operation of fermentation process. In fact, kinetic data must be available for modeling. The kinetic parameters of gluconic acid production by Aspergillus niger in batch culture was studied in this research at initial substrate concentration of 150, 200 and 250 g/l. The kinetic models used were logistic equation for growth, Luedeking-Piret equation for gluconic acid formation, and Luedeking-Piret-like equation for glucose consumption. The Kinetic parameters in the model were obtained by minimizing non linear least squares curve fitting. Keywords—Aspergillus niger, fermentation, gluconic acid, kinetic.