The composition, proteolysis, sensory and texture characteristics of low-fat white-brined cheeses (∼60% fat reduction) made from bovine milk and containing two commercial hydrocolloid-fat replacers ...(1% w/w Simplesse
® D-100 and 0.125% w/w Novagel™ NC-200) were examined throughout aging for 90
d. For comparison, the low-fat variant without fat replacers (L) and the full-fat cheese (F) were also studied. All the low-fat products showed reduced values for MNFS and yield, whereas the moisture and protein content significantly increased; however, the cheeses containing fat replacers had higher moisture and yield values than the L product. The extent of proteolysis and lipolysis in the low-fat white-brined cheeses made with the fat replacers significantly increased compared to the F cheese. The kinetics of
α
s1-and
β-casein degradation as well as the evolution of the peptide profile (reversed phase HPLC) were not largely affected by the hydrocolloids. For the cheeses containing fat replacers, the mean values of TPA (texture profile analysis) parameters and the maximum stress (
σ
max at 80% deformation on uniaxial compression) were significantly less than those of the L cheese, showing a great improvement in cheese texture when the fat replacers were included. The textural attributes of the product made with Novagel™ resembled more closely those of the F cheese. Significant correlations (
p<0.05) with negative slopes were obtained between the variables reflecting the degree of proteolysis and instrumental (TPA) texture parameters; such relationships were even stronger when the data were analyzed for each type of cheese separately. The rheological measurements showed an improvement in the low-fat cheeses containing fat replacers, but this was not clearly evident by sensory testing. Overall, the full-fat white-brined cheese was perceived as more elastic, less salty and had higher flavor and odor intensity scores than all low-fat variants. Although Simplesse
® (S) had a marked improving effect on cheese appearance, the product was rated as a harder cheese than its full-fat counterpart.
Teleme cheese was made from ovine, caprine and bovine milk with thermophilic, mesophilic, and mixed thermophilic–mesophilic cultures. Nine lots of cheese each time were made in order to study the ...physico-chemical and sensory changes of cheeses throughout ripening and storage up to 6 months. The rate of pH decrease was the fastest in cheeses made with the mesophilic culture and the slowest in cheeses made with the thermophilic culture, regardless of the kind of milk used. Moisture was higher in cheeses made from cows’ milk than in cheeses made from the other two kinds of milk. The highest fat content and yield were in cheeses made from ewes’ milk not being affected by starter culture used, the highest protein content was in cheeses made from goats’ milk whereas salt content was not affected by either the kind of milk or starter culture used. The use of mesophilic or mixed cultures resulted in cheeses of higher flavour scores than those of cheeses made with thermophilic culture. It is concluded that all three kinds of milk may be used in making Teleme cheese preferably by using a mesophilic or a mixed thermophilic and mesophilic starter culture.
Peptides were isolated from the water-soluble fraction of Feta cheese by reversed-phase HPLC in three successive steps. Peptide sequencing was performed by automatic Edman degradation. Most of the ...peptides originated from a αs1-casein (CN), especially from the N-terminal half of the molecule. Two peptides originated from the C-terminal domain of β-CN. Only one peptide, which was rich in histidine, originated from κ-CN. β-Lactoglobulin and α-lactalbumin were also identified in the water extract of Feta cheese. The origin of most of these peptides could be explained on the basis of known specificities of chymosin and lactococcal cell-wall proteinases.
Low-fat white-brined cheese was manufactured by a traditional procedure from bovine milk (70% fat reduction) containing two levels of an oat β-glucan concentrate (CEBA Foods AB) at 0.7% and 1.4% ...(w/w). For comparison two controls – a full-fat and a low-fat product without addition of the β-glucan concentrate – were also examined. The results indicated that as the fat content of cheese milk decreased, the fat, moisture in non-fat solids (MNFS) and yield values significantly decreased, and the moisture and total nitrogen values increased. The products fortified with the β-glucan concentrate exhibited higher yield values and significantly lower pH (at 60 and 90 days of storage) than the control samples. In accordance with the latter values, the HPLC analysis showed that incorporation of the β-glucan concentrate into the low-fat cheese milk led to a significant increase in the production of lactic, acetic and butyric acid throughout cheese ripening. Also, the extent of proteolysis in the treatments supplemented with the hydrocolloid significantly increased, especially at 60 and 90 days and was higher than the respective values of the control products. With regard to the rheological properties of the cheeses, incorporation of the β-glucan concentrate brought about amelioration in all the textural parameters of the low-fat product, as determined by large deformation mechanical testing and sensorial analysis; significant correlations (
p<0.01) between instrumental and sensory data for hardness were identified. However, the addition of the β-glucan preparation adversely affected cheese appearance and flavour in comparison with the control samples.
Web based search engines have been with us for a long time now. They proved to be an irreplaceable tool for researchers and Internet users all over the world. The exponential growth of the Internet ...has disclosed great challenges to these engines, as it is hard to maintain an accurate database of numerous web pages over time. This problem becomes wearisome, as it is often necessary to browse through several results before locating a web page that matches the given query. As today mobile devices are able to connect to the Internet through high-cost low-bandwidth wireless networks, this tactic can become very expensive. Motivated by these issues, we designed and implemented SearchSweep, a mobile agent based client-server system that uses existing search engine systems on the web to locate and download web pages. A refinement system on the server makes this solution ideal for mobile users, or users with limited bandwidth. The structure of SearchSweep platform is presented and the use of mobile agents on wireless devices is proposed as a way of attacking their limitations.
As the Internet became widespread, people saw it as a way of distributing content. But while the average bandwidth capacity is increasing, users around the world are trying to share more data. ...Although the servers are able to acquire more bandwidth, they cannot keep up with the rapidly increasing requests of the users. Several systems appeared that alleviate the server from the dissemination process. But such systems are not always suitable for disseminating highly anticipated files of considerable size. The evolution of peer-to-peer systems gave a new way of attacking this problem. Each user can assist the dissemination process by acting as a server as well. In this paper the way traditional systems meet users' demands is demonstrated, and simulation results of a peer-to-peer approach based on a mobile agent platform are presented. Our focus is on how different parameters can affect the dissemination process of a highly anticipated file in this network.
Peer-to-peer (P2P) file-sharing networks started out as a way to create a big pool of files to which anyone who participated had access. However, as the Internet evolved, these networks became one of ...the major enabling technologies. The traditional client-server paradigm does not always come through when great amounts of data need to be disseminated to numerous users. P2P systems became an alternative, relieving the server from becoming the congestion point. The purpose of this article is to show and analyze simulation results of a file being disseminated through two widely used approaches for P2P networks. Emphasis is given to the efficiency of each approach when demand on a highly anticipated file is simulated, as well as the benefits of the mobile agent-based itinerary algorithm proposed in this article.
As the average bandwidth capacity is increasing, users around the world demand shorter service time. While the servers are able to acquire more bandwidth, they can not keep up with the rapidly ...increasing requests of the users. Several systems appeared that alleviate the server from the dissemination process. The evolution of peer-to-peer systems gave a new way of attacking this problem. But as they got increasingly widespread, certain patterns became apparent. Uneven flow of data and interspersed congestion points compromised interdomain quality of service. We demonstrate how traditional systems meet users' demands, and present simulation results of a peer-to-peer approach based on a mobile agent platform. Our focus is on using the server's and the clients' resources in an optimum way to serve as many clients as possible in a certain period of time.
Yogurt ice cream made of 6.5% sheep's milk fat and 11.5% of nonfat milk solids (MSNF) derived by 83% from sheeps milk contained decreased lactose and increased protein by approximately 20% and 25%, ...respectively, compared to the conventional product from cow's milk. Acidity of the final product was from pH 4.4 to 4.9. Stabilizers that were tried were xanthan gum, guar gum and a commercial stabilizer at concentrations 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5%. Based on determinations of physical qualities as well as on the sensory evaluation of the yogurt ice cream, xanthan gum gave optimum results at 0.2% concentration, guar gum at 0.3% while the commercial stabilizer was partially satisfactory up to 0.5% concentration
Ninety-four commercial Teleme cheese samples were examined for aflatoxins produced by direct mold growth.
The mycoflora on the cheese and in the atmosphere of Teleme cheese plants also were ...monitored. Perncillium and Aspergillus genera were tested for alflatoxin production after growth on Teleme cheese at 25°C. In all cases, over 78% of the molds were Penicillium species. Aspergillus made up 3.8 to 3.9% and 0 to 7.3% of the mold on cheese and in the plant atmosphere, respectively. None of the commercial samples contained aflatoxins and none of the 448 Penicillium isolates was an aflatoxin producer. Of 22 Aspergillus species, one was capable of producing aflatoxins after direct growth on cheese. Because the physicochemical characteristics of Teleme cheese (high moisture, low pH, and medium salt concentration) favor mold growth, care should be taken to avoid contamination of the cheese by aspergilli.
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