FUNCTIONAL PROPERTIES OF GOAT AND BUFFALO MILK PROTEINS

د. محمود ابرهيم باحث بمعهد بحوث تكنولوجيا الاغذية 

ملخص رسالة الماجستير ( جامعة الاسكندرية )

SUMMARY AND CONCLUSIONS

The physicochemical properties of food proteins affect their functional properties of the food as texture, colour, flavour, water binding and stability. Probably the most important physicochemical properties are solubility, hydration, rheology, surface activity and gelation. Milk proteins, either caseins or whey proteins, due to their heterogeneity, range of physical properties and amphipolar characteristics, were used in food processing for multiple functions.  Most of research was focused on bovine milk proteins due to the dominance of such type of milk all over the world. However, little attentions were directed to evaluate the functional properties of non-bovine milk proteins.Therefore, this study was conducted to study different functional properties of both goat and buffalo milk proteins in order to gain some knowledge to evaluate these proteins for further application in food industry. To achieve such goals, various caseins (HCl, lactic, rennet) and casein- coprecipitate preparations were prepared by different methods. Meanwhile, the effect of some factors as concentration of protein, pH of the medium, trypsin treatment on functional properties of prepared proteins was studied. The obtained results revealed the following:

1. Goat milk proteins have higher significant (P≤ 0.05) degree of solubility than those of buffalo milk.
2. The solubility of both goat and buffalo milk proteins was protein concentration and pH dependent, i.e. the higher the concentration and pH value, the higher the solubility.
3. Goat and buffalo HCl-casein showed the highest solubility at pH 8 followed by lactic casein then rennet casein. But casein co-precipitate was characterization by very low solubility at all pH values comparing to the other caseins.
4. The emulsifying capacity (EC) of goat and buffalo caseins was concentration and pH dependent, i.e, the higher the concentration and pH value, the higher the EC.
5. Goat HCl-casein showed the highest EC at pH 8 and there was no significant (p≤ 0.05) change between lactic casein and rennet casein. But casein co-precipitate was characterization by very low EC at all pH values comparing to the other caseins.
6. Buffalo lactic -casein showed the highest EC at pH 8 followed by HCl-casein, and then casein co-precipitate. But rennet casein was characterization by very low EC at all pH values comparing to the other caseins.

7. Goat milk proteins (HCl- , lactic -, rennet casein and casein co-precipitate )  have higher significant (P ≤ 0.05) degree of EC than those of buffalo milk at all concentrations and pH values.
8. The viscosity of different goat and buffalo milk casein preparations as affected by concentrations. The viscosity of all casein preparations was significantly   increased by concentration increase. Meanwhile the two types of goat and buffalo milk casein preparations were not affected by the increase of pH from 7 to 8.
9. Goat milk casein coprecipitate is the proper preparation for the food application in order to obtain high viscous mixture followed by lactic casein. The viscosity of all goat milk casein preparations except rennet casein was pH independent.

10. At all pH values, the ascending order of   viscosity of goat and buffalo proteins  was HCl-casein, rennet casein, lactic casein and casein coprecipitate.
11. Over all results revealed that goat milk rennet casein and casein coprecipitate have significantly (p≤0.05) higher viscosity values than those of buffalo milk caseins but there were no significant differences between lactic casein and HCl-casein of both types of milk. Both types of casein preparations are similar in that HCl-casein had the lowest viscosity, while casein co-precipitate had the highest viscosity value.
12. The foaming capacity FC and foam expanded FE of goat and buffalo HCl-casein increased with the concentration increase. Meanwhile the FC and FE of buffalo HCl-casein were higher significant than that of goat HCl-casein at all concentrations and pH value.
13. The highest foam volume of buffalo HCl-casein was obtained at pH 7.0 for all casein concentrations. On the other side the highest FC of goat HCl-casein was obtained at pH 7.5.
14. The foam volume stability FVS of buffalo HCl-casein was higher than that of goat casein. The higher FVS was found at buffalo HCl-casein, concentration 1.00% and pH 8.0.
15. The FC and FE of goat and buffalo lactic casein were increased with the concentration increase at all pH value. The FC, FE and FVS of buffalo lactic-casein were higher than that of goat casein. The higher FVS was found at buffalo lactic casein, at pH 7.0 and concentration 1.00%.
16. The FC and FE of goat and buffalo rennet casein were increase with the concentration increase at all pH values. The FC, FE and FVS of buffalo casein were higher than that of goat casein.
17. The behaviour of buffalo rennet casein is different than that of goat rennet casein because the best foam stability of the former casein can be obtained at higher pH value and concentration than the latter casein.
18. The behaviour of goat and buffalo casein co-precipitate CCP is similar, the foam capacity of buffalo CCP is better than that of goat milk at higher concentrations and pH values.

19. The obtained  results revealed that the FVS of goat casein co-precipitate is higher than that of buffalo at  both pH 7.5 and 8.0.
20. The solubility of both goat and buffalo milk HCl-casein was significantly (p ≤ 0.05) increased then decreased by trypsin treatment for 5and 15 min, respectively.
21. The solubility of native and trypsin treated goat milk HCl-casein, lactic casein and casein co-precipitate was significantly higher than these of buffalo milk.
22. Trypsin hydrolysis at pH 7.0 for 5 min enhances the EC of goat HCl-casein and lactic casein as well as buffalo lactic casein and no HCl-casein. But the EC of casein co-precipitate of goat and buffalo milk is retarded by the same treatment under the same conditions.
23. The behaviour of HCl-casein of buffalo milk is different than any other casein preparations whether buffalo or goat milk. Meanwhile, the tryptic products of most of casein preparations in both goat and buffalo milk have lower viscosity than native proteins.

24. Trypsin treatment for 5 min of both types of casein resulted a significant increase in foam volume; followed by another significant increase after 15 min. the FC of buffalo HCl- and lactic casein hydrolysate was higher than that of goat casein.
25. The behaviour of foam stability of goat milk HCl-casein is completely different than that of buffalo milk, since the tryptic treatment enhanced the foam stability of the former but reduced that of the latter.
26. Trypsin treatment for 5 min of both types of casein resulted a significant increase in foam volume, followed by another significant increase after 15 min. The rate of foam volume increase was significantly  higher  in case of buffalo lactic casein than that of goat milk.
27. The behaviour of foam stability of goat milk lactic casein is completely different than that of buffalo milk, since the tryptic treatment enhanced the foam stability of the former but reduced that of the latter.
28. After trypsin treatment for 5 min of both types of casein co-precipitate have a significant increase in foam volume, followed by another significant increase after 15 min in case of goat but there was no significant change in case of buffalo milk casein co-precipitate.
29. The trypsin treatment had no effect on FVS of goat and buffalo casein co-precipitate.
30. Results showed also that goat and buffalo milk casein preparations were completely different in their electrophoretic behaviors due to the differences in charges and molecular weights. B) The behaviour of goat and buffalo milk casein preparations towards trypsin hydrolysis was entirely different. Since, buffalo lactic casein and casein coprecipitate were higher in proteolysis by trypsin than those of goat proteins, while goat HCl-casein has the opposite behaviour.

Conclusions

1. Goat and buffalo milk protein preparations are highly different in their functional properties.
2. All goat milk protein preparations are characterized by their higher solubility, emulsifying capacity than buffalo milk proteins, therefore they can be used in food application as beverages, baking, candy, soups, sausage and ice cream making.
3. Buffalo milk protein preparations are characterized by their higher foaming capacity and stability than those of goat milk, therefore they can be used in ice cream making, coffee whitener, foam milk, spongy cakes and whipped toppings.
4. To improve the functional properties of either goat and buffalo milk protein preparations, trypsin treatment for 5 min is recommended.

Utilization of Milk Protein Hydrolysate in Functional Beverage 

El Sayed, M. I,.; 1, 2 Awad, S.; 1 Wahba, A.; 1 Aisha, M. El Attar.1 and Zeidan, M2

د . محمود ابراهيم باحث بمعهد بحوث تكنولوجيا الاغذية (الاسكندرية )..مركز البحوث الزراعية 

ABSTRACT

The objective of this study was to utilize milk protein concentrate hydrolysate (MPCH) in special drinks as functional beverages and to study the acceptably of such drinks with fresh fruits and flavors. The milk protein concentrate was hydrolyzed by trypsin at pH 7.5 for 20 h. Protein hydrolysis was evaluated by SDS-PAGE and RPHPLC. Milk protein was completely hydrolyzed by trypsin after 20 h of incubations as there were no bands observed on the SDS-PAGE and broad peptides were separated by RP-HPLC as a source of bioactive peptides. The bitterness of milk protein hydrolysate by trypsin was eliminated by adding sweeteners (sucrose, fructose and sucralose). The reduction of bitterness was highly observed in fresh strawberry and mango juices when compared to flavored juices. However, the best score of sensory evaluation was in MPCH when it was treated by sucrose, fructose and sucralose without flavor compared to MPCH with strawberry flavor. MPCH that utilized in fresh mango juices and sweetened by sucrose, fructose and sucralose received the highest acceptability scores and lowest bitterness compared to all other treatments.

Key words: Milk protein, bioactive peptides, functional beverages.

ALEXANDRIA SCIENCE EXCHANGE JOURNAL, VOL.35, No.1JANUARY-MARCH 2014

الخواص الفيزيوكيماوية لثمار الدوم واستخدام مطحونها فى توليف بعد الاغذية الوظيفية 

د رضا عبد الحكيم حلمى عامر ..باحث بمعهد بحوث الحاصلات البستانية التابع لمعهد بحوث تكنولوجيا الاغذية  (الاسكندرية ) مركز البحوث الزراعية 

Antioxidant activity of milk protein hydrolysate in alloxan-induced diabetic rats

 د. محمود ابراهيم ..باحث بمعهد بحوث تكنولوجيا الاغذية  ( الاسكندرية ) مركز البحوث الزراعية 

ABSTRACT

We investigated the effects of milk protein concentrate (MPC) and milk protein concentrate hydrolysate (MPCH) as antioxidant agents in rats. Six groups of healthy (non-diabetic) and type-II diabetic rats were used: (1) healthy rats (control), (2) alloxan-induced rats (diabetic control group), (3) healthy rats treated orally with MPC, (4) diabetic rats treated orally with MPC, (5) healthy rats treated orally with MPCH, and (6) diabetic rats treated orally with MPCH. We concluded that treatment with MPC or MPCH reduced the level of thiobarbituric acid reactive substances in healthy and diabetic rats. Treatment with MPC or MPCH improved activities of antioxidant enzymes (catalase, superoxide dismutase, reduced glutathione, glutathione-S-transferase, and glutathione peroxidase) in healthy and diabetic rats. From the present data, we concluded that both MPC and MPCH contain potent antioxidants and could improve the health of rats or other animals with diabetes mellitus. Key words: bioactive peptide, type-2 diabetes, free radical, antioxidant enzyme

In Vivo Anti-diabetic and Biological Activities of Milk Protein and Milk Protein Hydrolyaste

د. محمود ابراهيم باحث بمعهد بحوث تكنولوجيا الاغذية ( الاسكندرية ) بمركز البحوث الزراعية 

Abstract

The effect of milk protein (MP) and milk protein hydrolysate (MPH) as Anti-diabetic agent were investigated in vivo using six groups of normal and type 2 diabetic rats. The results of this study showed that the treatments of diabetic rats by oral intake of MP or MPH significantly reduced the concentrations of plasma glucose, total lipids of blood plasma, triglycerides, total cholesterol, LDL and VLDL in rat plasma. Also, the treatments of diabetic rats by oral intake of MP or MPH significantly increased the globulin value and HDL, while the concentration of urea, creatinine and bilirubin were reduced. In addition, oral intake of MPH has no affective on acid phosphatase (ACP), alkaline phosphatase (ALP), alanine transaminase (ALT) and aspartate transaminase (AST) activities in blood plasma and liver of normal rats and protective its concentrations in diabetic rats. The present results concluded that MP and MPH could be used as anti-diabetic agents.

تأثير إضافة بعض جرعات من تفلة الزيتون وسلفات الأمونيوم على نمو واثمار أشجار صنفى العناب الهندى التفاحى والبلحى وقابلية ثمارهما للتصنيع. Science Exchange. J. VOL.32. (2011)No.4 OCTOBER.DECEMBER

د. عفاف محمد على يوسف*، د. وفاء على أمين**

* قسم بحوث البساتين- معهد بحوث البساتين- مركز البحوث الزراعية- الجيزة- مصر.

** قسم بحوث تصنيع الحاصلات البستانية- معهد بحوث تكنولوجيا الأغذية- مركز البحوث الزراعية- الجيزة-  

أجريت تجربة حقلية فى مزرعة خاصة غرب النوبارية- محافظة البحيرة- مصر خلال عامى 2009، 2010 لدراسة تأثير تركيزات مختلفة من تفلة الزيتون و سلفات أمونيوم على النمو الخضرى والمحصول وصفات جودة الثمار ومحتوى الأوراق والثمار من العناصر المعدنية وكذلك قابلية الثمار للتصنيع فى صنفى العناب الهندى التفاحى والبلحى . وقد أوضحت النتائج أن جميع المعاملات من التسميد العضوى والمعدنى أعطت زيادة معنوية فى  محتوى الثمار من البيتا كاروتين ومستخلص الإثير الخام والسكريات الكلية والمختزلة والغير مختزلة بينما أدت إلى إنخفاض محتوى الثمار من الألياف الخام. كما أنها أدت إلى زيادة المواد الصلبة الذائبة الكلية والفوسفور بالثمار وذلك فى الموسم الأول كما أدت إلى زيادة محتوى الثمار من الكلورفيل الكلى والرطوبة والبروتين الخام فى الموسم الثانى.وأدت المعاملات التى تحتوى على تركيز مرتفع من سلفات الأمونيوم مثل 3 كجم تفلة + 5 كجم سلفات أمونيوم والمعاملة 4 كجم تفلة + 4 كجم سلفات أمونيوم إلى زيادة المحصول (كجم/ شجرة) والمساحة الورقية (سم²) وطول الأفرع الثانوية (سم) بينما إنخفضت نسبة الحموضة والرماد بالثمار. المعاملة 6 كجم تفلة+ 2 كجم سلفات أمونيوم (محتوى عالى من تفلة الزيتون) كانت أفضل معاملة حيث أنها أدت إلى إرتفاع قياسات جودة الثمار مثل وزن وحجم الثمرة وكذلك ارتفاعها وقطرها وكذلك محتواها من فيتامين ج.كما أدت إلى زيادة محتوى الأوراق من البوتاسيوم والثمار من النيتروجين.وكانت الأختلافات معنوية بين صنفى العناب فى النمو الخضرى فيما عدا المساحة الورقية لصنف التفاحى الذى سجل قيمة أعلى من صنف البلحى فى الموسم الأول. وكان صنف البلحى متفوقاً عن التفاحى فى ارتفاع وحجم الثمرة ومحتوى الثمار من البيتا كاروتين والسكريات الكلية والمختزلة والغير مختزلة والمستخلص الخالى من النيتروجين والرطوبة والبروتين الخام ومحتوى الأوراق من الكلوروفيل الكلى ومحتوى الثمار من المواد الصلبة الذائبة (موسم أول).بينما سجل صنف التفاحى قيم أعلى من البلحى فى محتوى الثمار من الرماد وقيم أقل فى محتوى الثمار من الحموضة وقطر الثمار (موسم ثانى) وصلابة الثمار (موسم أول).وأوضحت الخواص العضوية الحسية لمنتجى الفاكهة المسكرة والبيورية المصنعين من صنفى العناب تقبل المتذوقين.

A field experiment was conducted in a private orchard, in West Nubaria , EL-Behera governorate, Egypt, during 2009 and 2010 seasons to study the influences of different combinations of olive pomace and ammonium sulphate fertilizers on vegetative growth, yield, fruit quality, leaf and fruit mineral contents and processing suitability of Tofahy and Balahy Indian ber varieties. The obtained results showed that, all combinations of organic and chemical fertilizers, resulted in a positive  effect, on fruit β-carotene, crude ether extract and total, reducing and non-reducing sugars, while decreased crude fiber. In addition, they enhanced total soluble solids, fruit phosphorus in the first season and fruit total chlorophyll, moisture and crude protein in the second one. Fruit yield (kg/ tree), leaf area (cm²) and secondary shoot length (cm) increased when the applied ammonium sulphate dose increased as in 3 kg OP + 5 kg AS or 4 kg OP + 4 kg AS combinations, while decreased fruit acidity and ash content. The combination of 6 kg OP + 2 kg AS treatment (higher amount of olive pomace) was the superior treatment, where it enhanced most fruit quality parameters, i.e. fruit weight, volume, height, diameter, vitamin C. Also, it increased leaf potassium and fruit nitrogen contents. The differences were insignificant between Tofahy and Balahy varieties in vegetative growth, except leaf area of Tofahy variety which was higher than Balahy in the first season. However, Balahy surpassed Tofahy in fruit height ,volume , β-carotene, total sugars, reducing and non-reducing sugars, nitrogen free extract (NFE), moisture , crude protein , total leaf chlorophyll and juice total soluble solids (1^st season). Tofahy variety showed higher values of fruit ash and lower juice acidity and fruit diameter (2^nd season) and firmness (1^st season).Organoleptic properties of ber fruits candied and pureé products revealed that panelists accepted the two products of the two varieties.

دراسات كيميائيه وتكنولوجيه علي نبات الشيكوريا واستخدامها في بعض الاغذيه الوظيفيه

J.Adv.Agric.Res.(Fac.Ag.Saba Basha) Vol:14 (2009) No.3 :735-755.

       منى مسعود¹، وفاء على أمين² ، أسمه أحمد الجندى³

1        – معهد بحوث المحاصيل السكرية – مركز البحوث الزراعية- الصبحية-اسكندرية-مصر.

2- قسم بحوث تصنيع الحاصلات البستانية – معهد بحوث تكنولوجيا الأغذية- مركز البحوث الزراعية- الصبحية-اسكندرية-مصر.

3- - قسم بحوث التغذية و الاغذية الخاصة – معهد بحوث تكنولوجيا الأغذية-  - مركز البحوث الزراعية- القاهرة-مصر^.

              يعتبرنبات الشيكوريا من النباتات الهامة فى  الصناعات الغذائية حيث انها مصدر للالياف التغذوية مثل  الأنيولين والسكريات العديدة وأيضا كمكون غذائى وظيفى له تاثير أيجابى للحفاظ على الصحة العامة و مقاومة الأمراض لذلك تهدف الدراسة الى التعرف على التركيب الكيماوى  لاوراق وجذور نبات الشيكوريا(Cichorium intybus l.) و إمكانية التخلص من المذاق المر من الجذور والأستفادة منها  كمكون غذائى في اعداد المقرمشات أو كبديل للنسكافيه لرفع القيمة الغذائية لتلك المنتجات. ولتحقيق الهدف تم تقدير التركيب الكيماوى و المعادن فى كل من الأوراق وجذور الشيكوريا وتقدير الأنيولين والسكريات الذائبة الكلية  كما تم أستخلاص المواد الفينولية وتقديرها والتعرف عليها بطريقة HPLC و التخلص من المرارة من الجذور باستخدام بعض المعاملات المختلفة ثم طحن تلك الجذور وأستخدامها فى تصنيع المقرمشات و مشروب النسكافية وأختبرت الخواص الطبيعية والحسية للمنتج الناتج وأوضحت نتائج التحليل الكيماوى أن جذور الشيكوريا تحتوى نسبة أعلى من الكربوهيدرات (89,41 %) والأنيولين (44,69 %) عن الأوراق (68,5 و10,95 % على التوالى). بينما تعتبر الأوراق مصدر جيد  للعناصر المعدنية  و خاصة الحديد . وكذلك فى  نسبة المركبات الفينولية الكليه التى تمثل 26.4و20 مجم/جم  فى الاوراق و الجذور على الترتيب. وأظهرت نتائج التعرف على المركبات الفينولية في المستخلصات باستخدام HPLC أن كلا من أحماض caffeic coumaricو و chlorogenic acid يمثلا أعلى نسبة فى المركبات الفينولية.كما أوضحت النتائج أن التحميص على 140م ^° لمدة 20 ق أدى الى أنخفاض فى ا لمرارة وأرتفاع فى محتوى الأنيولين  مقارنة بالنقع في ماء على 22 ± 2 م^° لمدة 24 ساعة أو45 م^° لمدة 3 ساعات (1:4 )، و في 0,75 %  محلول حامض الستريك (10:1) لمدة 24 ساعة . كما أوضحت نتائج الخواص الحسية  عدم وجود  أى فرق معنوي في الخواص الحسية للنسكافيه المستبدله بنسبة 50 % من جذور الشيكوريا المحمصة ونسبة 100 % نسكافيه كما أنها حسنت من درجات طعم المشروب. وقد نالت المقرمشات  قبول المحكمين  عند استبدال 10 % من دقيق القمح و25  % من الدهن بمسحوق جذور  الشيكوريا بعد ازالة المرارة بالنقع في الماء أو محلول حامض الستريك.

 

         Chicory is of interest to food  industry not only as a source of dietary fibers such as inulin and fructo-oligosaccharides  but also as a functional food ingredient that affects in maintaining good health and in preventing disease.  Therefore, the present work aimed to identify the chemical composition of chicory plant (leaves & roots), possibility of removing the bitter taste of roots and utilization of chicory roots in crackers and Nescafe' like product as products added value from this plant. To achieve this goal, chemical compositions as well as minerals of the leaves and roots of chicory plant were determined. Inulin and total soluble sugars were determined also phenols content were extracted and assayed. Phenolic compounds were identified by HPLC. Removing of bitter taste from  chicory roots was tried with different treatments ,then the samples dried and grounded to be use in crackers making and Nescafe'  .the produced product were tested with some physical factors and evaluated sensorial. The obtained results revealed that chicory roots contain high concentration of total carbohydrates (89.41%) and inulin (44.69%), while chicory leaves had lower concentration of both (68.50 and 10.95%   respectively). Leaves had higher content of minerals than the roots. It is a good source of minerals especially Fe   .Total phenolic content of chicory leaves and roots were 26.4 and 20 mg/g of dry matter expressed as Gallic acid equivalent, respectively. Caffeic acids, coumaric and chlorogenic acids were shown to be the major phenolic compounds in the methanolic extract of roots and leaves, respectively. Roasting at 140˚C for 20 minutes showed high inulin content and low bitter taste followed by soaking in water (1:4 w/v) at 22 ± 2˚C for 24 hrs; in 0.75% citric acid solution (1:10 w/v) for 24 hrs then in hot water (1:4 w/v) at 45˚C for 3 hrs. Using of 50% roasted chicory roots as a Nescafe' replacer had no significant effect on organoleptic properties but improved the drink^' s taste scores. Chicory powdered roots could successfully replace wheat flour (10%) and fat (25%) in producing cracker after debittering by soaking the roots in water or citric acid solution.