1,720,963 research outputs found
The composition of black cumin and use of black cumin and other essential oils as antioxidant in food technology
No full textGünümüzde gıdalarda mikrobiyel, fiziksel ve kimyasal özellikleri korumak ve gıdanın yapısını, dış görünüşünü,
tadını, kokusunu olumsuz yönde etkilemeyecek nitelikteki katkı maddelerinin kullanımına yönelik yoğun bir
eğilim bulunmaktadır. Bugüne kadar yapılmış çalışmalarda gıdaların depolaması sürecinde oluşabilecek en
önemli problemlerden biri olan oksidasyonu önlemek ve gıdaların raf ömrünü uzatmak için sentetik
antioksidanlar kullanılmıştır. Son yıllarda sentetik antioksidanların toksikolojik ve kanserojenik özelliklerinin
tespiti nedeniyle üretilen katkı maddelerinin gıdalara ilave edilmesinden kaçınılmaktadır. Bu nedenle gıdalara
ilave edilecek antioksidanlarda aranan en önemli özellik doğal olması, sentetik olmamasıdır. Antioksidan
kullanımında bir diğer kriter antioksidanların maliyetinin düşük olması tüketici tercihinde aranan önemli bir
faktördür. Antioksidan etkiye sahip bitkilerden birisi de çörek otu esansiyel yağıdır. Bu yağın tıbbi özellikleri
konusunda bazı çalışmalar yürütülmüş olmakla beraber, ne yazık ki bu bitkiden elde edilen ve antioksidan etkiyi
sağlayan uçucu yağların gıdalarda kullanımı hakkında yeterli sayıda bilimsel çalışmalar yapılmamış ya da
yapılan çalışmalarda elde edilen bulgular arasında çelişkili sonuçlar olduğu saptanmıştır. Bu derlemede, bugüne
kadar çörek otu uçucu yağının gıdalarda antioksidan olarak kullanımı, antioksidan aktiviteye sahip maddelerin
elde edilmesinde kullanılan farklı ekstraksiyon yöntemlerinin karşılaştırılması, çörek otu uçucu yağında bulunan
fraksiyonların termal stabilitesi, sentetik ve doğal antioksidanların özellikleri vs. konusunda yapılmış
çalışmaların sonuçları değerlendirilmiştir.Nowadays, there is an intense trend on using of additive materials which do not effect odor, appearance and flavor
of the foods negatively for preserving microbiological, physical and chemical properties of the foods. In the
studies which has been carried out until today, synthetic antioxidants have been used to prevent oxidation which is
one of the important problems during storage and extending the shelf life. In the recent years, including of
synthetic additive materials in foods has been avoided due to toxicological and carcinogenic properties of the
synthetics. For this reason, the most important desired property for the antioxidants is that they should be natural
and should not be synthetic. One of another criteria on using of antioxidants is low cost and it is important factor
for consumer preference. One of the plants having antioxidant property is black cumin essential oil.
Although studies were carried out on medicinal properties of this essential oil, sufficient work has not been
performed on using essential oil which has been maintained from this plant and has provided this antioxidant
effect in the foods or it is determined that there is contradictory between the results.
In this review, the results of the studies on using of black cumin essential oil in foods, comparing of techniques
extractions used for maintaining material having antioxidant effects, thermal stabilities of fractions including in
black cumin essential oil, properties of natural and synthetic antioxidants were evaluated
Heat induced changes on the Caseinmicelle and its influences on cheese making process
No full textZiel war, bisher fehlende Erkenntnisse zur thermischen Reaktivität der Caseinmicelle zu gewinnen, die bislang als sehr hitzestabil galt. Dazu wurde Milch in seine Hauptproteinfraktionen getrennt, so dass reines, v. a. molkenproteinfreies natives Casein erhalten wurde. Daran wurde mittels Dissoziations- bzw. Polymerisationsgradmessung, Erfassung von Oberflächenhydrophobizität und Voluminosität die tatsächliche thermisch bedingte Variabilität der Caseinmicelle erfasst. Diese Effekte wurden anschließend mit den Gelbildungseigenschaften von Casein bei der Käseherstellung korreliert. So wurde festgestellt, dass die thermischen Veränderungen der Caseinfraktion wesentlich größer sind, als bisher vermutet, denn in Anwesenheit der Molkenproteinfraktion waren die Effekte beider Fraktionen stets in bisher publizierten Arbeiten überlagert.The aim was to obtain insights regarding thermal reactivity of the casein micelle which has been considered so far thus very heat-stable. Milk was fractionated in its main protein fractions, so that pure, whey-protein-free native casein could be made available. By means of dissociation and/or polymerization degree measurement, ascertainment of surface hydrophobicity and voluminosity the actual thermally caused variability of the casein micelle was determined. These effects were then correlated with the gel formation characteristics of casein during cheese production. Thus, it was stated that the thermal changes of the casein fraction are substantially larger than so far assumed, because in presence of the whey protein the effects of both fractions were always overlaid
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Presence of aflatoxin M1 in cheese and the affecting factors of aflatoxin M1 concentration
Get PDFÜlkemizde toplam çiğ süt üretiminin yaklaşık %40'ı peynir üretiminde kullanılmaktadır ki bu 4-5 milyon tonluk bir çiğ sütün peynire işlendiği anlamına gelmektedir. Peynir, tüketim alışkanlıkları açsından vazgeçilmez bir üründür. Süt üretiminin önemli bir kısmının peynir sektörüne ayrıldığı ve tüketici kitlesinin her gruptan insanda kapsadığı göz önüne alınacak olursa üretilecek olan peynirin gıda kalite standartları ve gıda güvenliğine uygunluğunun denetlenmesi ve hassasiyetle takip edilmesi zorunluluğu kendiliğinden ortaya çıkmaktadır. Özellikle peynirin kaliteli bir sütten (bakteri içeriği ve somatik hücre sayısı düşük) elde edilmesi gerekliliği yanında, ayrıca sütte toksin oluşturan küf kontaminasyonu riskinin de bulunmaması gerekmektedir. Süt ve süt ürünlerinde bulunan en önemli küf Aflatoksin M1 (AFM1)'dir.
Çeşitli peynirlerde AFM varlığı hakkında günümüze kadar yapılmış olan ulusal ve uluslararası çalışmalarda belirlenen AFM düzeylerinin Uluslararası (Avrupa Birliği ve FAO/WHO Kodeks Alimentarius) Mevzuatlara ve Türk Gıda Kodeksine uygunlukları değerlendirilmiştir. AFM 'in peynirdeki konsantrasyonları konusunda ülkeler arasında ve ülkemizde de oldukça farklı sonuçlar söz konusudur. Bu nedenle, konu bilimsel çalışmalar kapsamında aydınlatılmıştır.In our country, 40% of total crude milk is used in the cheese production which means 4-5 million tons of milk is
processed to cheese. Cheese is an indispensable product in terms of consumption habits. The suitability of the
cheese to food quality standards and food safety is emerged as considering the bulk of the milk production is
reserved for cheese sector and the composed a heterogenic consumer group. In addition to the necessity of high
quality milk usage (low bacteria content and somatic cell count) in cheese production and also the milk should not
have toxigenic fungus contamination risk. The most important fungus in milk and milk products is Aflatoxin M . 1
In this study, the appropriateness of aflatoxin M levels in various types of cheeses to international legislations 1
(European Community and FAO/WHO Codex Alimentarius) and Turkish Food Codex were investigated via
national and international publications. Different results were obtained for aflatoxin M concentrations in cheeses 1
among countries including our country. Therefore, the issue was clarified in the context of scientific studies
Production of yogurt analogs from peanut milk (extract) using microbial transglutaminase and two different starter cultures
No full text<p>This study produced and analyzed peanut milk yogurt analogs made with microbial transglutaminase (mTGase), two different starter cultures (an EPS and a non-EPS producer), and additional peanut pulp to solve low viscosity and textural problems in peanut milk yogurts. The EPS starter culture was used to determine whether it could help solve these problems. Six yogurt analogs were produced, three with YC350 and three with YoFlex starter cultures. SDS-PAGE analysis showed that the intensity of protein bands decreased with increasing enzyme concentration. The microstructure of yogurt analogs made with the EPS starter culture had a less porous, tighter matrix and creamier structure. Diacetyl and acetaldehyde, important volatile compounds of yogurt, were also present among the 34 volatile compounds identified. In sensory analyses, yogurt analogs produced with non-EPS cultures received higher scores, especially in appearance, odor, and consistency. The number of yogurt bacteria reached 8 log10 cfu/g, which shows that peanut milk is a suitable substrate for growing yogurt bacteria. No significant changes occurred in water holding capacity or syneresis during storage. Among the two yogurt samples (C and F), EPS-added yogurt yielded better results regarding firmness. However, the shelf life of peanut milk yogurt analogs was 14 days.</p>
Variations on the Author
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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