ORIGINAL_ARTICLE
EFFECT OF THE CALF RENNET PASTE ON SOME PHYSIOCHEMICAL AND MICROBIOLOGICAL PROPERTIES OF BUFFALO'S PICKLED SOFT CHEESE
The effect of rennet paste on soft cheese making and quality was investigated. Two different calf rennet pastes (CRP1 and CRP2) were used. The rennet clotting time (RCT) increased as the fat content of the salted milk increased. Skim milk samples containing 12 % NaCl with CRP2 decreased, compared with the CRP1. The cheeses made by using the different rennets did not differ in their moisture, protein and fat content or in the total nitrogen, which resulted from proteolysis. The cheese produced with rennet CRP2 had the highest lipolysis than the cheese made with CRP1. The FFAs in the soft cheese made with CRP2 rennet paste was higher than the cheese made with CRP1. The value of TVFA increased during cheese ripening. The higher concentration of TVFA might be attributed to higher degree of fat hydrolysis being occurred by residual activity of enzyme and microflora. Fresh cheese showed the lowest thiobarbitutic acid (TBA) value compared to ripened cheese. Cheese produced by CRP2 showed higher TBA values than that of CRP1 cheese sample. There was a remarkable inhibition in the growth of spore forming bacteria and yeasts & moulds. The α1-I- casein band was found in all cheese samples. Sensory quality attributes of cheese were improved with the prolongation of the ripening period. Ripening of cheese resulted in better flavor as well as body and texture.
https://jfds.journals.ekb.eg/article_81832_8c402c208e3b340a3b5ffefa1bb149fb.pdf
2011-01-01
1
11
10.21608/jfds.2011.81832
Rennet pastes
Soft cheese
Lipolysis
proteolysis
Hygienic quality
Z.
Hassan
1
Food Sci. Dept., Fac. of Agriculture, Ain Shams University, Cairo, Egypt.
AUTHOR
O.
Aita
2
Food Sci. Dept., Fac. of Agriculture, Ain Shams University, Cairo, Egypt.
AUTHOR
ORIGINAL_ARTICLE
تأثير المثبطات و التجفيف على تثبيط الإنزيمات البکتينية في الطماطم.
تمت الدراسة باستخدام طماطم من السوق المحلي صنف (Lycopersicon esculentum) و معاملتها بحمض الستريک 2% أو الصوديوم ميتابيسلفايت 0,05% و تجفيفها في صورة شرائح ولفائف ومسحوق ماعدا المجموعة الکنترول , وإجراء التحليلات الإنزيمية البکتينية (إنزيم البکتين ميثيل استيريز PME و إنزيم بولي جلاکتورونيزPG) لشرائح الطماطم ولفائف الطماطم و مسحوق الطماطم المخزنة على درجة حرارة الغرفة 25-30 ْم في مکان مظلم لمدة أربعة شهور , وکانت التحليلات شهرياً من بداية التخزين و حتى الشهر الرابع , عملية التجفيف أدت إلى انخفاض في نشاط إنزيم PME بنسبة تتراوح من 77,83 ٪-93,45 ٪ في منتجات الطماطم المجففة المعاملة بحمض الستريک 2 ٪ أو بصوديوم ميتا بيسلفايت 0,05% , مع ملاحظة زيادة في النشاط خلال مدة الحفظ , کذلک أدى التجفيف إلى انخفاض نشاط إنزيم PG بنسبة تتراوح من 78,8 ٪– 83,9٪ في منتجات الطماطم المجففة المعاملة بحمض الستريک 2٪ أو بصوديوم ميتا بيسلفايت 0,05% مع زيادة النشاط بزيادة مدة الحفظ (أربعة شهور) على درجة حرارة الغرفة (25-30 ◦م) . ومعاملة الطماطم بحمض الستريک 2% أو الصوديوم ميتابيسلفايت 0,05% قبل التجفيف أدى إلى تثبيط إنزيم البکتين ميثيل استيريز PME و إنزيم بولي جلاکتورونيز PG التي تحت الدراسة .
https://jfds.journals.ekb.eg/article_81834_2160596408bfbf798bdf7eb1442b7a22.pdf
2011-01-01
13
21
10.21608/jfds.2011.81834
فاطمة
الصبحي
1
قسم التغذية وعلوم الأطعمة-کلية العلوم الطبية التطبيقية-جامعة أم القري- المملکة العربية السعودية
AUTHOR
سهير
قنديل
2
معهد بحوث تکنولوجيا الأغذية-مرکز البحوث الزراعية-الجيزة
AUTHOR
ORIGINAL_ARTICLE
EFFECT OF STARTER CULTURE ON THE QUALITY AND YIELD OF KARISH CHEESE MADE FROM BUFFALO’S MILK
Karish cheese was made from fresh buffaloes' skim milk (0.5% fat) using a commercial starter culture DOM 1® (Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris (1:1)) and with natural starter from good quality karish cheese. Four treatments were made by using 1 & 2% natural starter culture (YS-1 and YS-2, respectively) and with 1 & 2% of DOM 1® starter culture (DS-1 and DS-2, respectively). Yield of the resultant cheeses were calculated. Chemical, microbiological and sensory characteristics of cheeses were monitored when fresh and during 60 days of storage at 5±2°C. Gross composition of all resultant cheeses was within the Egyptian legal limits for Karish cheese. The highest cheese yield (25.4%) was obtained when 2% of DOM 1® starter culture was added (DS-2). This increase in the cheese yield of DS-2 was associated with an increase in the cheese moisture content by 2.7% compared with YS-1 and 1.1% compared with YS-2 treatments. The pH values were decreased during storage period, but both YS-1 and YS-2 treatments had lower pH-values than DS-1 and DS-2 treatments. The highest values of SN and SN/TN were observed in the DS-2 cheese treatment. This could be an indication of more proteolysis occurred when 2% of the DOM 1® starter culture was used. DS-1 and DS-2 treatments showed a reduction in the losses of TS and TN contents in the pickling solution during storage compared with YS-1 and YS-2 treatments. It was also observed that YS-1 and YS-2 treatments had higher total viable bacterial and mold & yeast counts than that in DS-1 and DS-2 treatments. On the other hand, there was a slight increase in the total sensory score of the DS-2 treatment. It can be concluded that manufacture of karish cheese by using 2% DOM 1® improved cheese yield, organoleptic properties and decreased losses of cheese components in pickling solution.
https://jfds.journals.ekb.eg/article_81835_57f3e647e07e918163e036e1e4545629.pdf
2011-01-01
23
32
10.21608/jfds.2011.81835
Karish – starter – storage period – buffaloe’s milk
M.
Hamad
mnour20002005@yahoo.com
1
Food Sci. and Dairy Dept., Fac. Agric., South Vally Univ., Qena, Egypt.
LEAD_AUTHOR
ORIGINAL_ARTICLE
UTILIZING OF POTATO STARCH RESIDUE STREAM TO PRODUCE FATTY ACIDS AND OTHER PRODUCTS BY Saccharomyces cerevisiae (Y- 1646)
Some fatty acids and other important products can be obtained from potato washing residue stream produced during Chips manufacturing, which hydrolyze by hot acid H2SO4 1% v/v 60 min under semianerobic conditions as economical source by Saccharomyces cerevisiae (y- 1646). Saccharomyces cerevisiae was able to utilize from this residual and production an acceptable amount of fatty acid and other important products. 2, 3 –dihydroxypropyl ester was found in higher levels (568.1 gl-1) and was followed by hexadecanoic acid (221.4 gl-1), and oleic acid (omega 9) 2.1 gl-1 at 35 ºC after 36 h from addition of ZnCl2 (0.4 gl-1). Study recommends intensive investigation in this research point to enhance the production of that extremely important compound.
https://jfds.journals.ekb.eg/article_81836_a8fca65215317f878ae8d0d33f9830f6.pdf
2011-01-01
33
41
10.21608/jfds.2011.81836
residue stream
fatty acid
fermentation
Saccharomyces cerevisiae
Soumia
Darwish
1
Food Science and Technology Dept., Fac. Agric., Assiut Univ., Egypt
LEAD_AUTHOR
ORIGINAL_ARTICLE
THE EFFECT OF ADDING CARROT PEEL FIBERS AND VITAMIN A ON IRON BIOAVILABILITY IN BISCUITS
The present work aimed to study the possibility of preparing biscuit samples made from wheat flour substituted with different levels of carrot peels 5%, 10%, 15% and 20% as a source of fibers and vitamin A. Raw materials and biscuits were analyzed chemically, physically, rheologically and organoleptically. Iron bioavailability also evaluated. The obtained results showed significant differences in moisture, protein, fat, fibers, ash and vitamin A contents in raw materials and all biscuit samples, while there were no significant differences in total carbohydrates of all biscuit samples. Biscuit sample contained 15% carrot peels showed the highest levels of Fe, Ca, and Cr significantly. Evaluation of organoleptic properties indicated that the best two samples were biscuit samples substituted with 10% and 15% carrot peels, respectively. Hematological measurements and biological results showed that biscuit samples of 10% carrot peels produced high levels of blood heamoglobin (13.40g/dl), hematocrit (43.82%), RBCs (4.980millions/ml3) and serum iron (184.00µg/dl). Generally, biscuit samples contained up to 10% carrot peels in the presence of vitamin A showed good results.
https://jfds.journals.ekb.eg/article_81838_aff99caa03ba349603be7f64c4efa88f.pdf
2011-01-01
43
58
10.21608/jfds.2011.81838
Mona
Khalil
1
Food Science Dept., Fac. Agric., Mansoura University, Egypt.
AUTHOR
Amalika
Eldahshan
2
Food Science Dept., Fac. Agric., Mansoura University, Egypt.
AUTHOR
R.
Eldengawy
3
Food Science Dept., Fac. Agric., Domietta, Mansoura Univ., Egypt.
AUTHOR
M.
Elabsy
4
Food Science Dept., Fac. Agric., Domietta, Mansoura Univ., Egypt.
AUTHOR
ORIGINAL_ARTICLE
BIOACTIVE COMPOUNDS OF FERMENTED SOYBEAN NATTO AS ANTIOXIDANT AND ANTIMICROBIAL AGENTS.
Soybean and its products became one of the most important functional foods due to its bioactive compounds (isoflavones and bioactive peptides), which have a greet health benefits to human being. In this study, it was prepared a fermented soybean natto with different treatments: drying natto with oven, solar, undervacuum, and extracting them with different solvents to check its antioxidant and antimicrobial activities. Results showed that, acetonitrile extract had the highest amount of peptides followed by methanol extract then water came in the last order. On the other hand, acetonitrile extract had the strongest antioxidant and antimicrobial activities, meanwhile water and methanol extracts had a close effect in general, but still methanol extract had the higher activities than water extract. Methanol extracted all of total isoflavones and some of bioactive peptides, acetonitrile extracted bioactive compounds and some of isoflavones. Upon correlation of these results, it was found that the highest antioxidant and antimicrobial activities excess in acetonitril extract. Therefore, it was assumed that the antioxidant and antimicrobial activities of natto came from both, isoflavones and bioactive peptides, but bioactive peptides had stronger activities.
https://jfds.journals.ekb.eg/article_81840_0cf44a589f3fbe83018feb20d981b112.pdf
2011-01-01
59
70
10.21608/jfds.2011.81840
antioxidant
Antimicrobial
Isoflavones
Natto
Bioactive peptide
Marwa
Mahmod
1
Dept. of Food Tech., National Research Center.
AUTHOR
Ferial
Abu-Salem
2
Dept. of Food Tech., National Research Center.
AUTHOR
M.
El-Kalyoubi
3
Dept. of Food Sci., Fac. Of Agric., An Shams Univ.
AUTHOR
A.
Gibriel
4
Dept. of Food Sci., Fac. Of Agric., An Shams Univ.
AUTHOR