THE EFFECT OF FREEZING-THAWING AND MARINATION TIME ON COOKED CHICKEN BREAST MEAT QUALITY

Marination is oft en used to improve the yield and quality of chicken breast fi llets. Th e eff ects of freezing-thawing prior to marination and marination holding time on the instrumental and sensory properties of cooked marinated chicken fi llets were investigated. Fillets were marinated fresh or stored at -18 oC and then thawed prior to marination (frozen-thawed). Fillets were soaked in marinade for 1.5 h and 20 h and then cooked at 175 oC for 45 minutes for determination of cooking loss, Warner-Bratzler shear force, color properties, juiciness and sensory properties. Marinade uptake was greater in fi llets marinated for 20 h, both fresh and frozen-thawed, than in fi llets marinated for 1.5 h. Cooking loss was lowest for fresh unmarinated fi llets (19.30%) and signifi cantly lower (P < 0.05) comparing to frozenthawed fi llets marinated for 20 h (44.73%). Th e highest numerical value of color parameter lightness was found in fresh fi llet marinated for 1.5 h. Th ere were no signifi cant diff erences between all examined fi llets regarding color properties redness and yellowness. Th e fi llets marinated for 20 h, both fresh and frozen-thawed were found to be signifi cantly more tender (P < 0.05) as indicated by lower shear force values (13.96 N and 12.88 N, respectively) and higher sensory scores for tenderness (7.00 and 6.50, respectively) as compared to other investigated fi llets. Furthermore, fresh fi llets marinated for 20 h had the highest mark for the overall sensory acceptability (95.00% of maximum quality).


INTRODUCTION
Marination is the process of applying a water-based solution composed of ingredients such as salt, sugar, oil, organic acids, herbs and food additives such as aroma enhancers, antioxidants and antimicrobials (Björkroth, 2005;Haute et al., 2016). Marinades are incorporated into meat by soaking, massaging, tumbling, or injecting (Parks et al., 2000). Originally, marinating was used to preserve the meat product over a longer time. Today, marinating is adopted by restaurants and industry in order to change the fl avor profi le of products, improve meat tenderness and juiciness, as well as to enhance yield by increasing retention and water content (Mielnik et al., 2008;Bianci et al., 2009) and is especially used for poultry products (Barbanti et al., 2005). Market forms of marinated poultry include whole birds, cut-up parts, boneless meat, and chopped and formed items. Many products sold in the raw, unmarinated state will be marinated by the retailer or by the consumer in the home prior to sale or consumption, respectively (Smith and Acton, 2010).
Th e functionality of marinades is dependent on the ingredients in aqueous solution. Th e most common ingredients in commercial marinades are NaCl, some type of phosphate and herbs and spices. Sodium chloride is a natural fl avor enhancer that improves the taste and aroma of meat products. Th e addition of sodium chloride promotes uptake of water due to the electrostatic repulsion and partially solubilization of proteins (Bianci et al., 2009; Alvarado and McKee, 2007). Herbs and spices are usually added to provide a variety of fl avors and aromas to marinades and to off set (harmonize) the bland chicken meat taste (Parks et al., 2000).
Some previous studies have investigated the infl uence of processing variables such as marinade ingredients and concentration, marination duration (the time course for marinade absorption), temperature, and chicken breast meat freezing-thawing on fi nal product quality attributes (Heath and Owens, 1991;Xiong and Kupski, 1999; Bowker and Zhuang, 2017; Fenton et al.; Zheng et al., 2000). Th e formation of ice crystals during meat freezing can disrupt muscle cells and cause the loss of product structure that does not recover when thawed (Kaale and Eikevik, 2014; Leygonie et al., 2012).
Th e objective of this study was to determine the eff ects of fresh neverfrozen chicken breast meat and breast meat that was frozen and thawed prior to marination and marination holding time on fi nal product quality attributes.

Raw materials
Th e chicken carcasses used in the present study were obtained from a local processing plant. Chilled chicken carcasses (n = 40) were cut to the basic anatomical parts. Fresh breast meat was divided into two halves, one half was im-mediately marinated, and the other half was frozen and stored for 10 days, and marinated aft er defrosting. Chicken breast meat samples were distributed into 6 groups and the marinating processes were performed as shown in Table 1.

Marinating process
Weighed and individually identifi ed fresh and defrosted fi llets were soaked in marinade in proportion of 1.25 kg marinade per 1.00 kg meat. Th e marinade consisted of salt (2.08%), sugar (4.00%), cinnamon powder (0.03%), dried thyme (0.03%), ginger powder (0.03%), mustard seed (0.17%) and pepper (0.17%). Th e content of spices is expressed in % in relation to water. Th e fi llets were marinated at 2 °C for 1.5 h (F1 and D1) and for 20 h (F2 and D2) by soaking in plastic boxes. Chicken fi llets from control groups were cooked without prior marination.

Marinade uptake
Th e samples weight was recorded before and aft er marinating. Aft er the preset marinating time, the parts were removed from the marinade and drained for 10 min before determining the marinade retention. Calculation for marinade uptake was as follows: marinade uptake (%) = (marinated weight -raw weight) / raw weight x 100

Cooking procedure
Before cooking, the samples were individually weighed, enwrapped in aluminum foil and introduced in the convection air oven when temperature reached the preset value. Th e cooking temperature was set at 175 o C for 45 min. Aft er cooking, samples were cooled at room temperature for 1 h and then analyzed for cooking loss, color, texture and sensory characteristics. Th e calculation of cooking loss was as follows: cooking loss (%) = (marinated weight -cooked weight) / marinated weight x100

Color determination
Th e color was determined instrumentally, on the fresh cut of cooked and cooled fi llet, with Minolta Chroma Meter CR-400. Color characteristics were expressed by CIE L*a*b* system (lightness-L*, redness and greennessa*; yellowness and bluenessb*). Color measurements were made in duplicate.

Mechanical texture analysis
Shear force evaluation was conducted on cylinder samples taken from the center of each fi llet, longitudinal to the muscle fi bers. Th e cylinders were 1.27 cm in diameter. A Warner-Bratzler blade, using testing machine Texture Analyser TA XP (Stable Micro System, Godalming, England), was used to shear the samples across to the muscle fi bers. Six measurements were performed on each sample to obtain mean values. A cross speed of 5 mm/s was applied using the 5 kg load cell. Mean values were expressed as shear force (N).

Juiciness
Juiciness was measured using the method of Gujral et al. (2002) with slight modifi cations. A meat sample (0.5 g) was taken from the center of the cooked and cold fi llet and placed between a pair of pre-weighed fi lter paper and between two plexiglass plates and pressed for 1 min (maximally connected and tightened screws). Th e fi lter paper was weighed aft er pressing and the percentage of extracted juice was determined as follows: Juiciness (%) = (weight of fi lter paper aft er pressing -weight of fi lter paper before pressing/weight of sample) x 100

Sensory analysis
A panel consisting of nine trained members of diff erent ages performed sensory evaluation. Evaluations were performed according to a 7-point scale descriptive system, from 1 to 7. Each mark was ascribed a distinctive quality Arhiv veterinarske medicine, Vol. 10, No. 2, 33 -44, 2017 Ivić M. … et al.: Th e eff ect of freezing-thawing... level, as presented in Table 2. Th e overall sensory quality was evaluated as total sum of mean scores for the sensory attributes.

Statistical analysis
Th e eff ects of sample type (fresh or frozen-thawed) and marination time on the variables studied were analyzed by Factorial ANOVA (Statistica 13.2 -Dell Inc., 2016). Th e Duncan's post hoc test was performed for comparison of mean values. Diff erences were considered signifi cant at P < 0.05.

RESULTS AND DISCUSSION
Increasing the marination time signifi cantly (P < 0.05) increased the amount of marinade uptake by the chicken breast fi llets, in both fresh and frozen-thawed fi llets (Figures 1 and 2). Marinade uptake of frozen-thawed fi llets was numerically lower in comparison with fresh fi llets (14.27% and 16.50%, respectively) for longer marination time (20 h). Bowker and Zhuang (2017) found similar results for marinade absorption of fresh and frozen-thawed fi llets vacuum-tumbled for 45 minutes. Chan et al. (2011) had shown that freezing signifi cantly aff ected biochemical and functional properties of proteins in turkey breast meat, thus altering the functionality attributes of raw poultry meat. Signifi cant eff ect (P < 0.05) on cooking loss was observed for sample type (fresh or frozen-thawed fi llets), marination time and interaction eff ect (sample type x marination time) (Table 3). Frozen-thawed fi llets marinated for 20 h (44.73%) had the highest numerically cooking value.
Instrumental color parameters are presented in Table 3. Fresh chicken breast fi llets unmarinated and marinated for 1.5 h diff er signifi cantly (P < 0.05) in comparison with frozen-thawed fi llets unmarinated and marinated for 1.5 h, with respect to lightness values (CIE L*). However, no signifi cant diff erence was observed regarding fresh and frozen-thawed fi llets marinated for 20 h (82.90 and 82.26, respectively). Th e lightness of all examined samples of fi llets was dependent upon the sample type (Table 3). Redness and yellowness were not aff ected by sample type, marination time and interaction eff ect of these two factors.
Tenderness has been identifi ed as the most important factor aff ecting consumer satisfaction and perception of taste (Naveena et al., 2004). Warner-Bratzler shear force (WBSF) is an important indicator related to meat tenderness (Zhao et al., 2012;He et al., 2015). One of the ingredients of three-spice powder mixture used for samples marination was ginger powder. Ginger, beside antioxidant and antimicrobial, has strong proteolytic activity (Bhaskar et al., 2006;Naveena et al., 2004). Signifi cantly (P < 0.05) lower WBSH values were observed in both fi llets marinated during 20 h compared to unmarinated fi llets and fi llets marinated for 1.5 h (Table 3). Longer marination time may have increased meat tenderness by enhancing muscle fi ber disruption (Naveena et al., 2004;Bhaskar et al., 2006;He et al., 2015).
Th e results of juiciness show that the unmarinated fresh fi llets had the highest value while the frozen-thawed fi llets marinated for 20 h had the lowest value (41.86% and 26.67%, respectively) ( Table 3). Th ese results could be correlated with the results of cooking loss, thus, unmarinated fresh fi llets had the lowest cooking loss, while the frozen-thawed fi llets marinated for 20 h had the highest value of cooking loss (19.30% and 44.73%, respectively). Marination time did not have signifi cant eff ect on cooked fi llets juiciness, while sample type signifi cantly aff ected the previously mentioned property.
Sensory property odor of examined fi llet samples was in average evaluated as "very good", except frozen-thawed fi llets marinated for 20 h which were ascribed a highest mark 7 ("extreme good") ( Table 1). However, above mentioned sensory property was signifi cantly infl uenced only by sample type. In general, other evaluated sensory properties of examined fi llets were found to be signifi cantly aff ected by the sample type. Taste of fresh fi llets marinated for 20 h was marked signifi cantly higher (P < 0.05) as compared to other examined fi llets. Likewise, fresh fi llets marinated for 20 h were evaluated significantly better (P < 0.05) than other samples with regard to sensory properties of juiciness and tenderness. Higher marks for juiciness and tenderness of previously mentioned fi llets can be explained by higher marinade uptake. Th e higher sensory mark for tenderness for fresh fi llets marinated for 20 h may have been in correlation with lower shear force value for these samples, than for other investigated samples. As well, aforementioned fi llets had the highest (95.00% of maximum quality) and frozen-thawed unmarinated fi llets had the lowest mark for the overall sensory acceptability (83.39% of maximum quality) (Figure 2).

CONCLUSION
Th is study evaluated the impact of sample type (fresh and frozen-thawed fi llets) and marination time on cooking loss, color properties, Warner-Bratzler shear force, juiciness and sensory properties (odor, taste, juiciness and tenderness) of chicken breast meat. Marination time signifi cantly aff ected cooking loss, WBSF values and most of the sensory properties (taste, juiciness and tenderness). However, sample type signifi cantly aff ected cooking loss, lightness, juiciness and all investigated sensory properties.