Mehmet Murat Karaoğlu

Microbiological Characteristics of Part-Baked White Pan Bread During Storage

In this study, white pan breads part-baked 10, 15, and 20 min with and without added calcium propionate were stored at 20°C (room temperature) for 3, 5, and 7 days and at 4°C (refrigerator temperature) for 7, 14, and 21 days. After storage, the baking time of part-baked breads was completed to the baking time of control breads (25 min). Total aerobic mesophylic bacteria (TAMB), coliform bacteria, yeast and mold, and Bacillus spore counts of breads were determined before and after the second baking. While TAMB, yeast and mold counts were 8-log CFU/g in dough, it was measured as 6 and 2-log CFU/g before and after the rebaking process, respectively. Microorganism counts of the part-baked breads without Ca-propionate stored at room temperature increased in significant amounts. However, the second baking process after storage contributed to the re-freshness of breads and decreased the microorganism counts. The levels of water activity (aw) for breads with and without ca-propionate stored at different temperatures and time profiles approximately ranged from 0.92 to 0.89 after the rebaking process and did not significantly affect the microorganism counts. However, addition of calcium propionate in the bread formulation significantly decreased TAMB, coliform bacteria, Bacillus spore, and yeast and mold counts, depending on decrease of pH levels. It was found that the microbiological quality of the rebaking bread with Ca-propionate after part-baking for 10 and 15 mins and storage at both room and refrigerator temperature was much higher than that of the other.In this study, white pan breads part-baked 10, 15, and 20 min with and without added calcium propionate were stored at 20°C (room temperature) for 3, 5, and 7 days and at 4°C (refrigerator temperature) for 7, 14, and 21 days. After storage, the baking time of part-baked breads was completed to the baking time of control breads (25 min). Total aerobic mesophylic bacteria (TAMB), coliform bacteria, yeast and mold, and Bacillus spore counts of breads were determined before and after the second baking. While TAMB, yeast and mold counts were 8-log CFU/g in dough, it was measured as 6 and 2-log CFU/g before and after the rebaking process, respectively. Microorganism counts of the part-baked breads without Ca-propionate stored at room temperature increased in significant amounts. However, the second baking process after storage contributed to the re-freshness of breads and decreased the microorganism counts. The levels of water activity (aw) for breads with and without ca-propionate stored at different temperatu...

Effects of Corn Oil and Broccoli on Instrumental Texture and Color Properties of Bologna-Type Sausage

The effects of substitution of sheep tail fat with corn oil (50%) and the addition of broccoli (0, 5, or 10%) on the instrumental texture and color properties of bologna-type sausage were investigated during chilled storage (90 days at 4°C). Thiobarbituric acid-reactive substances and pH analysis were also carried out in fresh and storaged samples. The substitution of sheep tail fat by corn oil had very significant (P < 0.01) effects on the color scores (L*, a*, and b*) and textural properties of samples. The use of broccoli affected significantly (P < 0.01) color scores and hardness, gumminess, and chewiness values. Storage time had significant effects (P < 0.01) on hardness, springiness and cohesiveness, and color scores. The use of corn oil in bologna-type sausage decreased thiobarbituric acid-reactive substances value. However, at the end of storage this value was not over 15 μmol MDA/kg in sausage with animal fat. The pH values were not below 6.1 at the end of the storage.

The effects of cooking time and sugar on total phenols, hydroxymethylfurfural and acrylamide content of mulberry leather (pestil)

The effects of glucose syrup (0, 20, and 40%), sucrose syrup (0, 20, and 40%) and cooking time (10 and 20 min) on the chemical characteristics of mulberry pestil were investigated by replacing glucose syrup and sucrose syrup with mulberry syrup. Changes in glucose and sucrose syrup concentrations significantly affected invert sugar, sucrose and total soluble solids content of mulberry pestils. The invert sugar values of mulberry pestil increased with the addition of glucose syrup, but decreased with the addition of sucrose syrup. An increase in levels of sucrose or glucose syrup resulted in an increase of the lightness of colour values; however, an increase in cooking time reduced the lightness of colour of mulberry pestil. When sucrose and glucose syrup were added, an increase in pH values of samples but a reduction in titratable acidity was detected. Replacing glucose syrup with mulberry syrup in the formulations resulted in a decrease in the amount of hydroxymethylfurfural and acrylamide formed in mulberry pestils. The reducing effect of glucose syrup on hydroxymethylfurfural and acrylamide formation was much greater than the effect of sucrose syrup.

Part-Baked Products

Baked or bakery products are very wide in varieties, including breads, rolls, cookies, cakes, pies, muffins, biscuits, doughnuts and pastries. It is an important part of a balanced diet and a wide variety of such products can be found in the supermarket shelves (Stanley et al. 2007). Bakery products, especially bread, cake, rolls, muffin, pastry, and other similar products have a limited shelf life. Physicochemical changes such as staling and firming, and microbiological spoilage such as yeast, mould, and bacterial growth reduces the shelf life of these products. Staling in these products results decreased consumer acceptance and thereby great economic losses. Because bakery products are an important part of the diet of people in many countries, the economic losses arising from staling are extremely important. For this reason, considerable attention has been given on staling of bakery products. Several studies have been reported to extend the quality and shelf life by retarding staling (Karaoglu and Kotancilar 2006).

Farklı Depolama Tiplerinin Buğday Biti [Sitophilus granarius L. (Coleoptera: Curculionidae)]’nin Gelişmesi Üzerine Etkisi

Bu calismada, farkli depolama sekli (tane-basak), tane nemi (% 12, 14, 16), depolama sicakligi (10, 20, 30 ˚C) ve depolama surelerinin (3, 6 ay) depo zararlisi olan bugday bitinin (Sitophilus granarius L.) sayisi ve zarar verdigi tane orani uzerine etkisi arastirilmistir. Bu calismada, tane ve basak halinde Bezostaya ve Krik ekmeklik bugday cesitleri kullanilmistir. Depolamanin baslangicinda kontrollu sartlarda olusturulan depolama ortamlarina her uygulama icin bes adet bocek birakilmis ve depolama suresince tanelere verdigi zarar ve bocek sayisindaki artis belirlenmistir. Depolama suresince, Krik bugdayinin depolandigi ortamda Bezostaya cesidine gore daha fazla bocek gelisimi ve daha fazla yenik tane olusmustur. Tane nem miktarinin, depolama sicakligi ve suresinin artmasi, hem yenik tane miktari hem de bocek sayilarinda onemli derecede artisa neden olmustur. Basak halinde depolanan bugdaylarda hem yenik tane hem de bocek sayilari, tane halinde depolanmis bugdaylara gore onemli derecede dusuk cikmistir. Bu nedenle, basak halinde depolanan bugdaylar tane halinde depolanan bugdaylara gore bocek zararina karsi daha dayanikli bulunmustur.

Besinsel Lif Kaynağı Olarak Enzime Dirençli Nişasta / Resistant Starch as a Dietary Fiber

OZET: Enzime direncli nisasta (EDN) kavraminin ortaya cikmasiyla nisastanin biyo-yararliligi ve ozellikle yetiskinlerde diyet lif kaynagi olarak kullanimi konusunda yeni bir arastirma alani dogmustur. EDN’nin tatli, beyaz renkli ve urun dokusunu asgari derecede etkileyen guzel partikul boyutuna sahip olusu; onun fonksiyonel ozellikleri ve avantajlari olarak gorulmektedir. EDN’nin pasta ve biskuvi gibi bazi gidalarda ingredient olarak kullanimi besinsel liflerin renk, doku vb. ozelliklerde sebep oldugu sorunlarin onune gecmektedir. Bununla birlikte EDN’nin vucutta gosterdigi faydali etkiler diyet lifininkine oldukca benzerdir. Kisa zincirli yag asitlerinin olusumuna katkida bulunmasi EDN’nin en onemli fizyolojik etkisi olarak gosterilmektedir. Anahtar Kelimeler: Enzime direncli nisasta, besinsel lif, KZYA. ABSTRACT: With discovery of the concept of resistant starch (RS) the new investigation field appear about the bioavailability of starch and in its utilize as a source of dietary fiber, especially in adults. It is accepted that having a bland flavor, white appearance and nice small partical size are advantage and functionality of RS. The usage of RS as an ingredient in some foods (pasta, biscuit etc.) avoid undesied color and texture which caused by dietary fiber. In addition to that, RS exhibits similar beneficial effects in human body to that is dietary fibre. It is commonly accepted that improving production of short chain faty acids (SCFA) in large intestine is the most important physiological effect of resistant starch intake. Keywords: Resistant starch, dietary fibre, SCFA.

Tahıl Ürünlerinde Camsı Yapıya Geçiş Sıcaklığı ve Önemi / Glass Transition Temparature And It’s Importance In Cereal Products

OZET : Camsiliga gecis, bir materyalin fiziksel, mekaniksel, elektiriksel, termal ve diger ozelliklerinde zaman, sicaklik ve su aktivitesine bagli olarak meydana gelen, sureklilik arz etmeyen bir gecis olarak karakterize edilebilir. Yari kristalize katilar (polimerler) hem amorf hem de kristal bolgelere sahiplerdir. Polimerlerin amorf bolgelerinde elastigimsi ve camsi durumun meydana geldigi sicaklik camsi gecis sicakligi(Tg) olarak adlandirilmaktadir. Camsi liga gecis yari kristalize katilarin sadece amorf bolgelerine has bir ozelliktir. Firin urunlerinde nisasta ve gluten yari kristalize polimerlerdir. Firin urunleri endustrisi icin nisasta ve gluten bilesenlerinin termal davranislarinin anlasilmasi cok onemlidir. Durum diyagramlarinda camsi gecis noktasinin belirlenmesinde, genelde differential scanning calorimetry (DSC) metodu yaygin olarak kullanilmaktadir. Termo-mekaniksel analiz (TMA) ve diger salinim metotlari daha hassas metotlar olmasina ragmen fazla tercih edilmemektedir. Gida materyallerinin mekaniksel ozelliklerinde camsi gecis sicakliginin etkisi oldukca onemlidir. Viskozitedeki hizli degismenin bir sonucu olarak gerceklesen yapiskanlik, gevreklik, cokme, retrogradasyon enzimatik ve enzimatik olmayan reaksiyonlar gibi degisikliklerin cogu camsiliga gecis sicakligi uzerinde yer almaktadir. Depolama sirasinda ekmekteki degisikliklerin bir karakteristigi olan ekmek sertligi, stabil kristal yapidaki nisasta makromolekul zincirinin yeniden duzenlenmesi nedeniyle de olusabilmektedir.xa0 Nisastanin retrogradasyonu ozellikle bu urunlerin camsiliga gecis sicakligi uzerindeki sicakliklarda depolanmalarina atfedilmektedir. Tahil urunlerinde bayatlama, urun bilesenleri arasinda yeniden dagilan sudan kaynaklanmaktadir. Firin urunlerinde bayatlama duzeyi, urunlerin camsiliga gecis sicakligi ve depolama sicakligi arasindaki sicaklik farki dikkate alinarak kontrol edilebilir. Su aktivitesi ve camsiliga gecis sicakligi, gida stabilitesini belirlemek amaciyla tespit edilmesi gereken iki onemli kriter olarak kullanilmaktadir. Anahtar kelimeler: Camsiliga gecis sicakligi , tahil urunleri, depolama stabilitesi, ABSTRACT : Glass transition is a time, temperature and water activity dependent transition, which is characterized by a discontinuity in physical, mechanical, electrical, thermal, and other properties of a material. Semi-crystalline solids are having both amorphous and crystalline regions. The temperature at which the transition in the amorphous regions of polymers between the glassy and rubbery state occured is called the glass-transition temperature (Tg). The glass transition is a property of only the amorphous portion of a semi-crystalline solid. Starch and gluten in baked products are semi crystalline polymers. Understanding the thermal behavior of starch and gluten components is very important for the bakery industry. Most of the transitions defined in the state diagram are commonly measured by DSC method using appropriate protocol. The thermo-mechanical analysis (TMA) and other oscillation methods are less commonly used, however these methods are more sensitive. The effect of glass transition on the mechanical properties of food materials is fairly important. Many of these changes (e.g. stickiness, crispness, retrogradation, and collapse, enzymatic and nonenzymatic reactions) are resulted from the rapid changes in viscosity that takes place above the glass transition temperature. Bread crumb hardening, the changes in bread characteristics during storage, can be due to the reorganization of the starch macromolecule chains in a stable crystalline structure. Starch retrogradation especially affects products with storage temperatures above their Tg. Staling in cereal products can also result from water redistribution among the product components. The rate of staling in bakery products is controlled by the temperature difference between the storage and glass transition temperatures of the product. Water activity and glass transition temperature concepts were used to investigate the between the two distinct criteria of food stability. Keyword: Glass transition, cereal products, storage stability

Tahıl Ürünlerinde Aroma Maddeleri: II. Kek, Pirinç, Mısır, Nişasta / Aromatic Compounds In Cereal Product: II. Cake, Rice, Corn And Starch

OZET : Pisirilmis pirinc, 2-asetil-1-pirolinin hakim oldugu patlamis misir aromasina benzer aroma icermektedir. Pismis pirinc aromasinda etkili olan aldehitler linoleik asit iceren lipidlerin peroksidasyonu ((E,E)-2,4-Dekadienal, hekzanal, (E)-2-nonenal) ya da oleik asit iceren lipidlerin peroksidasyonu (nonanal, oktanal, dekanal) ile olusmaktadir. Pismis tatli misirin karakteristik kokusu dimetilsulfit tarafindan olusturulmaktadir. Taze patlamis misir aromasinda en onemli aroma maddeleri 2-asetil-1-pirolin, (E-E)-2,4-dekadienal, 2-furfuriltiol, 4-vinil-2-metoksifeol, 6-asetiltetrahidropiridin, 2-propionil-1-pirolin ve asetilpirazindir. Tavada patlatma sirasinda sure uzadikca ve sicaklik arttikca 6-asetiltetrahidropiridinin degredasyonuna sebep olmakta ve daha fazla stabil asetilpirazin olusumuna firsat vermektedir. Anahtar Kelimeler: Aroma, pirinc, kek, misir, nisasta Aromatic Compounds In Cereal Product: II. Cake, Rice, Corn And Starch ABSTRACT : The cooked rice has aroma which is dominated with is 2-acetyl-1-pyrolin like popped corn aroma. Aldehydes effected on cooked rice aroma is formed by peroxidation of lipid contained linoleik acid ((E,E)-2,4-Decadienal, hexanal, (E)-2-nonenal) or oleik acid (nonanal, octanal, decanal). Flavour of cooked sweet corn was formed by dimethylsulfid. 2-acetyl-1-pyrolin, (E-E)-2,4-dekadienal, 2-furfuriltiol, 4-vinil-2-metoksifeol, 6-acetyltetrahydropyridine, 2-propionyl-1-pyrolin is the most important volatiles in fresh popped corn. When corn is popped in pan, with the increasing of time and temperature cause degredation of 6-acetyltetrahydropyridin resulting formation of more stable acetylpyrazine. Key Words: Flavoring, rice, cake, corn, starch