The inhibitory effect of grape seed powder (GSP) on lipid oxidation in chicken nuggets during frozen storage for 5 months was investigated. Chicken nuggets were prepared by dipping into batter containing GSP and pre-fried at 180°C and then stored at −18°C. Prefried chicken nugget crusts showed antioxidant properties. Primary oxidation products, determined by the peroxide value (POV) and conjugated diene (CD) concentration, gradually increased until month 2 and then declined, which is an indication of secondary lipid oxidation. Thiobarbituric acid reactive substance (TBARS) values slowly increased during the first 2 months of storage and then slightly decreased. However, at the end of the storage period, the levels were increased to 0.4 mg MDA/kg meat and were lowest in 10 % GSP (0.104 mg MDA/kg meat). The para-anisidine values (pAV) increased in all samples during storage. Generally, samples treated with GSP had lower POV, pAV, TBARS, and CD values compared to the control. These findings indicated that GSP significantly (p<0.05) retarded lipid oxidation in precooked chicken nuggets.

The effects of the addition of grape seed powder (GSP) on the thermorheological properties of frying batters were investigated in this study. Thermal properties, including gelatinization (T G ) and melting (T m ) temperatures, as well as enthalpies (ΔH G , ΔH m ), were determined by a differential scanning calorimeter (DSC). The addition of GSP decreased the T G and T m as the GSP levels increased. When compared with the control batter, the addition of GSP significantly decreased the apparent viscosity and viscoelastic modules (G′, G′′). The mechanical spectra of batters carried out at 15-80°C showed a transition from fluid-like to gel-like behavior. The batter pickup values were found to be directly proportional to the batter viscosity. Both water retention capacities (WRC) and consistency index values (K) of the batters were significantly affected by the GSP addition and temperature (p < 0.05). Grape seeds have health-promoting components on a scientific basis; thus, this study provides helpful results in the development of novel frying batters.

ÖzetBu çal›flma kapsam›nda; bu¤day unu, m›s›r unu, tuz ve kabartma ajan› ile haz›rlanan basit kaplama hamuruna de¤iflik oranlarda üzüm çekirde¤i tozu (GSP) eklenerek kaplanan ve peynir alt› suyu tozu çözeltisine (WPS) dald›r›larak kaplanan tavuk eti parçalar›n›n ön k›zartma iflleminden sonra nem, protein, ya¤ ve yüzeyde yap›flma miktarlar› belirlenmifltir. Bunlar›n yan› s›ra, doku, taramal› elektron mikroskobu (SEM) ve tiyobarbitürik asit (TBA) analizleri yap›lm›flt›r. Yap›lan çal›flma sonucunda GSP miktar› artt›kça nem (%66.20±0.71 -68.22±0.38), protein (%16.16±1.36 -19.73±1.40) ve yüzeyde yap›flma miktar› (%26.27±0.43 -36.13±0.71) art›fl gösterirken ya¤ miktar›nda (%8.18±0.17 -4.78±0.54) azal›fl meydana gelmifltir. En düflük ya¤ miktarlar› WPS'ye dald›r›larak haz›rlanan örneklerde bulunmufltur. Uygulama yap›lan örneklerde ön k›zartma iflleminden sonra da antioksidan aktivite gözlenmifl ve uygulama yap›lan tüm örneklerin TBA de¤erleri (23.30±1.61 -27.17±1.12 mg MDA/kg) kontrol ile karfl›laflt›r›ld›¤›nda daha düflük seviyelerde olsa da önemli bir fark belirlenmemifltir (P>0.05). Elde edilen sonuçlara göre kaplama harc› malzemesi olarak GSP kullan›m› ve WPS'ye dald›rma ifllemi kaplama harc›n›n kalitesinin gelifltirilmesinde bir potansiyele sahiptir.Anahtar kelimeler: Üzüm çekirde¤i tozu, antioksidan aktivite, ön k›zartma, kaplama harc›, tavuk nugget. EFFECTS OF GRAPE SEED POWDER AND WHEY PROTEIN ON QUALITY ATTRIBUTES OF CHICKEN NUGGETS AbstractIn this study, it was investigated that the moisture, oil, protein and batter pick up contents of chicken meat pieces prepared by adding different amounts of grape seed powder (GSP) to simple batter containing wheat flour, corn flour, leavening agent and salt and products dipped whey protein isolate solution (WPS) after battering. Along with these analysis texture, scanning electron microscopy (SEM) and thiobarbituric acid analysis (TBA) were carried out. As a result of this study, it was observed that protein (16.16±1.36 -19.73±1.40 %), moisture (66.20±0.71 -68.22±0.38 %) and batter pick up values (26.27±0.43 -36.13±0.71 %) increased with increasing GSP amount while oil content (8.18±0.17 -4.78±0.54 %) were found to decrease. The lowest oil contents were found in batters those dipped into WPS. Antioxidant activity was observed also after pre-frying and although TBA values (23.30±1.61 -27.17±1.12 mg MDA/kg) of all treated samples were lower when compared to control sample, significant differences were not determined (P>0.05). In order to these results, use of GSP as a batter ingredient has a potential to improve the quality characteristics of batter.

In this study, two different treatments and their effects on quality characteristics of chicken nuggets after three different cooking procedures were evaluated. Batters containing grape seed powder (GSP) dipped into whey protein solution (WPS) were compared with control (without any treatment) using deep fat frying, conventional oven and microwave oven. Batters contained equal amounts of wheat and corn flours with 5 and 10% GSP. All batters exhibited thixotropic behavior, and the GSP enhanced batters had lower viscosities. The lowest pickup values and highest total color change (ΔE) values were observed in deep fat fried samples. The microwaved samples had higher crispness levels and pickup values but achieved lighter colors that were identical to those of the pre-fried samples. Samples dipped into WPS provided reduced oil absorption consistent with their moisture contents. The scores for overall acceptability tended to decrease with the increase in GSP amount. PRACTICAL APPLICATIONSThis study shows the effects of grape seed and whey protein solution treatments on batter quality as well as their interaction with cooking procedures. Although negative impressions toward battered and fried food products have been increased, consumers are becoming aware of health and nutritional food concepts. Therefore, new strategies are necessary in order to obtain healthier battered and fried foods without compromising the sensory quality. Grape seed powder is a promising ingredient as well as whey protein solution treatment as a post dip for improving the major components of frying batter in terms of textural properties, flow behavior, oil uptake and batter pickup. The results of this study could be helpful in the development of novel fried nuggets that include natural antioxidants having similar characteristics with grape seed powder.

Su aktivitesi kavram›, 1950'lerde g›dalar›n dayan›kl›l›¤›n›n belirlenmesinde kullan›lm›fl olsa da baz› k›s›tlamalara sahiptir. Bu k›s›tlamalar›n üstesinden gelebilmek amac›yla cams› geçifl kavram› önerilmifltir. Ancak günümüzde bu kavram›n da tüm g›da ürünleri ve depolama koflullar›nda dayan›kl›l›¤›n belirlenmesi için yeterli olmad›¤› belirtilmektedir. Yap›lan araflt›rmalarda su aktivitesi ve cams› geçifl kavram›n› birlikte kullanarak baz› yaklafl›mlar önerilmekte ve bu yaklafl›mlar, cams› geçifl koflullar› ile su miktar›n›n su aktivitesinin bir fonksiyonu olarak çizildi¤i grafikler ve durum diyagramlar›ndaki makro ve mikro bölgelerden oluflan grafikler olarak karfl›m›za ç›kmaktad›r. Bu yaklafl›mlara ek olarak; kullan›lan engel teknolojilerini, g›dan›n kalitesini etkileyen su miktar›n› ve dayan›kl›l›¤› tan›mlamak için kritik s›cakl›k terimi gelifltirilmifl ve su hareketlili¤i kavram› ortaya at›lm›flt›r. Bu özet çal›flmas›nda su aktivitesi kavram›, cams› geçifl kavram› ve bunlar›n birlikte kullan›m› ile günümüzde yeni tan›mlanan moleküler hareketlilik kavram›n›n g›dalar›n dayan›kl›l›¤›n› tan›mlamada nas›l kullan›ld›¤› konular› üzerinde durulmufltur.