Influence of Goji berries on oxidative changes, microbiological status and chemical properties of sausages

  1. Mitev1*, A. Kuzelov1, E. Joshevska2

1Department of Food Technology, Faculty of Agriculture, University „Goce Delchev”, 2400 Shtip, Republic of Macedonia

2Department of Food Technology, Faculty of Biotechnical sciences, University “St. Kliment Ohridski”, Bitola, Republic of Macedonia

(Manuscript received 11 January 2018; accepted for publication 28 February 2018)

Abstract. The objective of this study was to investigate the influence of dried and minced goji berries over the oxidative changes (acid level, peroxide value), microbiological status and chemical properties on semi-durable sausage vacuumed and kept at a temperature of +4°С. Therefore, four types of sausages were made. The study was carried out on the 1st, 10th, 25th, 35th, and 50th day of the production of the sausage groups. The acid level of all examined groups of sausages is increasing, and the highest increase is registered in the control group of sausages (2.08). During the storage of the sausages, the peroxide value increased from the first to the fiftieth day. The presence of Listeria monocitogenes, Salmonella, Escherichia coli, Staphylococcus aureus was examined as well as the number of aerobic bacteria. In all examined groups, none of the abovementioned bacteria were identified. During the storage of sausages, the number of aerobic bacteria ranged from 2.08 to 2.93 log/CFU/g, which was much lower than the permissible limit (7.00 log/CFU/g) according to the national legislation. The fruit of goji berry doesn’t have a significant effect on the chemical composition of the studied sausage groups.

Organoleptic properties of white yam (Dioscorea rotundata poir) as affected by autoclaving time

  1. Ahmed1*, Y.B. Kiri2, M.S. Abubakar3

1Department of Crop Science, Adamawa State University, Mubi, Adamawa State, Nigeria

2Department of Animal Production, Adamawa State University, Mubi, Adamawa State, Nigeria

3Department of Soil Science, Federal University Dutse, Jigawa State, Nigeria

(Manuscript received 22 October 2017; accepted for publication 31 January 2018)

Abstract. This experiment examined the effect of processing white yam (Dioscorea rotundata poir) using autoclave under different heating times with the main objective of assessing its effects on the organoleptic properties (colour, mealiness, taste, softness and wetness). Yam tubers were washed, peeled and chopped into chunks. Treatments consisted of yam autoclaved at the temperature of 121oC and pressure of 100 kPa using five different autoclaving times (0, 5, 10, 15 and 20 min) laid out in a Completely Randomized Design (CRD). Descriptive sensory analysis was conducted by five trained panelists using a 7-point descriptive scoring method. Data collected were subjected to Analysis of Variance using SAS (1999). Least Significant Differences (LSD) tests were used to compare means that showed significant difference at P≤0.05. The results show that, autoclaving time had positive influence on organoleptic properties of white yam. The effect was more apparent on yam autoclaved for 5 minutes and therefore, recommended to be adopted for improved sensory attributes of boiled white yam.

Residue analysis of difenoconazole in apple fruits grown in Republic of Macedonia

  1. Jankuloska1*, I. Karov2, G. Pavlovska1

1Faculty of Technology and Technical Sciences – Veles, “St. Kliment Ohridski” University – Bitola, Dimitar Vlahov 57, 1400 Veles, Republic of Macedonia

2 Faculty of Agriculture, University Goce Delchev, 2400 Shtip, Republic of Macedonia

(Manuscript received 18 July 2017; accepted for publication 11 November 2017)

Abstract. The purpose of this research was to determine the residue analysis of difenoconazole in apple fruits from Resen region, Republic of Macedonia. Analyzed were two varieties of apples, Golden Delicious and Idared. Samples were taken from two different locations in Resen in the year 2016. Difenoconazole analysis was performed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) after a previous extraction of residue by applying the QuEChERS method. The obtained concentrations of residues of difenoconazole are compared with the maximum residue limit regulated by the Macedonian legislation. Analyses showed that the concentration of difenoconazole in both varieties of apples from two different locations is in the range of 0.01 to 0.41 mg/kg. In certain development phase of the apple fruits the concentration reaches 80 times lower concentration than the maximum limit. The data show that apple fruits can be safely consumed according to the recommended maximum residue limit (MRL) for difenoconazole in apples (0.8 mg/kg). Statistical processing of the data suggests that there is no significant difference between samples but presence of difenoconazole in apple fruits from both locations is with significant difference.

Role and importance of the awareness for whey in dairy sector at an international level

M. Yılmaz1*, H. Celik2, A.D. Karaman3, K. Celik4

1Department of Animal Science, Faculty of Agriculture, Adnan Menderes University Aydın, Turkey
2Economics and administrative sciences, Çanakkale on Sekiz Mart University, Çanakkale, Turkey
3Department of Dairy Technology, College of Agriculture, Adnan Menderes University, Aydın, Turkey 4Department of Animal Science, Faculty of Agriculture, Çanakkale on Sekiz Mart University, Çanakkale, Turkey

(Manuscript received 6 June 2017; accepted for publication 2 November 2017)

Abstract. The WHY-WHEY? is a training project supported by the EU with regard to the Erasmus+ program aiming at promoting awareness for it. In this study, the surveys carried out with the participants of a total of 4 workshops in Turkey, Italy, Poland and Hungary were evaluated. Whey is the main dairy by-product, rather than a waste, which is obtained during the coagulation of milk casein in cheese making and which is considered as a residual aqueous solution of lactose containing protein and minerals. Survey results indicated that whey is a significant source and it could facilitate the production of some different alternative products. However, there is a great lack in the knowledge and the awareness in this sense. For this reason, it could be said that more detailed surveys and result analyses could offer a solid base to develop a training course and didactic materials in a way that could completely meet the needs of the sector.

Carcass traits and meat quality of different slow growing and fast growing broiler chickens

M. Oblakova1, N. Mincheva1, P. Hristakieva1, I. Ivanova1, M. Lalev1, Sv. Georgieva2

1Agricultural Institute – Stara Zagora, 6000, Bulgaria
2Department of Genetic, Breeding and Reproduction, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 3 July 2017; accepted for publication 5 October 2017)

Abstract. The experiment was conducted in the breeder farm of department Population genetics, reproduction and technologies of poultry and rabbits at the Agriculture Institute of Stara Zagora. Five lines from the National Gene Pool of Bulgaria: line Ss (Sussex), line E (Barred Plymouth Rock), line NG (New Hampshire), line F (NG x Red Rhode Island), line L (White Plymouth Rock) were used as maternal forms in the crossing schedule and line M (Cornish) as a paternal form for production of slow-growing broilers. The birds were grown to 84 days. Feeding was done with compound feeds according to the age: starter (1/14 days of age), grower (14/28 days of age), finisher (28/84 days of age). By the end of the experiment, slaughter analysis was performed with 3 female and 3 male broiler chickens per group with live weight corresponding to the average of each genotype. The live weight was determined, as well as the grill weight, the weights of cuts (breast, thighs, wings), edible offal (heart, liver, gizzard) and abdominal fat. On the basis of these data, the slaughter yield and body parts ratios were calculated. The data for the live body weights of birds at slaughtering indicated the highest values for group V – 4040g, followed by groups ІV and ІІ – 3271.67g and 3186.67g, respectively (p<0.05). There was a statistically significant difference between the sexes with superiority of male birds (p<0.001). In the other 3 groups, breast meat percentage ranged from 19.48 to 19.84%. The share of thighs from the grill was the greatest in slow-growing chickens from group II – 33.01%, followed by group І – 32.35%, group IV – 32.18%, and the lowest- in groups ІІІ and V (31.91% and 31.18%, respectively). The analysis of data exhibited a significant effect of the genotype on water content of breast meat (resp. Dry matter), with lower values in slow-growing birds from group III – 73.19% (p<0.05), whereas in the other groups it ranged between 73.44 and 73.62%. The dry matter higher percentage was associated with better lavor of meat. The analysis of the effect of genotype on meat protein content showed that protein content was the highest in the breast of slow-growing chickens from group III- 24.89% and lowest in the breast meat of conventional broilers from group V – 23.86% (p<0.05). In the other 3 groups, it ranged from 24.55 to 24.59%. The protein content of thighs was the lowest in slow-growing birds from group I- 19.49%, and the difference was the highest when compared to groups II and III, also slow-growing (p<0.05). With respect to the thigh fat content, it was the highest in slow-growing chickens from group IV (5.84%), followed by fast-growing from group V (5.33%) and the lowest- in slow-growing birds from group І – 4.12% (p<0.05). The analysis of data showed a statistically significant effect of the sex on water content (p<0.001), fat (p<0.001) and ash (p<0.01). In males, thigh meat contained water and ash and in females more fat. The interaction of genotype and sex effects were important for thigh meat fat content, with highest values in fast-growing females from group V – 5.98% and lowest in slowly growing males from group I – 3.88% (p<0.001). Weak but statistically significant interaction between both factors was found with respect to thigh protein and ash (p<0.05). The highest protein content was established in slow-growing females from group IV (19.81%), whereas thigh ash was with highest percentage in slow-growing males from group II (1.11%).

Mathematical methods for assessment and analysis of honey yield data for Bulgaria and the European Union for the period 1961-2014

N. Keranova*

Department of Mathematics, Informatics and Physics, Faculty of Economics, Agricultural University-Plovdiv, 4000 Plovdiv, Bulgaria (Manuscript received 30 May 2017; accepted for publication 27 September 2017)

Abstract. The objective of this work is to assess the average yields of bee honey for the period from 1961 to 2014 for all countries of the European Union. For this purpose, a single-factor analysis of variance was used. As a result of the surveys, it was found that the highest average yield of honey in the EU is in Germany (20541.91 t) and Spain (20253.43 t), while the lowest yield is in Ireland (199.74 t) and Luxembourg (133,2 t). Data on the production of bee honey in Bulgaria by regions from 2006 to 2014 were also analyzed, and mathematical models were made, reflecting the relationship between the respective honey yields and the survey period. The data on the basis of which the study was carried out are from the FAOSTAD database and the Agro-statistical reference book for 2000-2014 of the “Agro-statistics” Department of the Ministry of Agriculture, Food and Forestry of the Republic of Bulgaria.

Sensory and instrumental texture analysis of Bulgarian commercial pates

M. Tonchev1, T. Atanasov1, A. Todorova1, Ts. Atanasova1, N. Shtrankova1, M. Momchilova2 G. Zsivanovits2

University of Food Technologies (UFT), 4000 Plovdiv, Bulgaria

Food Research and Development Institute (FoodRDI), 4003 Plovdiv, Bulgaria

(Manuscript received 2 June 2017; accepted for publication 22 August 2017)

Abstract. The aim of this study was to characterize the textural differences between Bulgarian commercial pates with different ingredients and to adapt the used methods for later application in texture analysis of sterilized meat products. Texture parameters were studied by sensory and instrumental methods. The sensory panel was stated from students in similar age and was asked to fulfill a questionnaire about their likening the poultry pates bought from the commercial network. Nine points sensory scales were used, about appearance, colour, spreadability by knife to bread, flavor, consistency, taste, aftertaste and overall likening. The panelists were asked to rank the pates based on their colour, spreadability and consistency. Instrumental texture parameters – texture profile and spreadability work, were analyzed by Stable Micro Systems texture analyzer in Texture Profile Analysis (TPA) and compression methods. For further analysis of spreadability, the probes were scanned by flatbed scanner before and after compression and their area ratio was measured by image analysis method. The results of sensory analysis show that, the pate with duck meat received the highest liking based on the overall liking, followed by pate with turkey meat and pate from chicken meat and liver and the lowest liked was the pate with goose meat. Based on the sensory spreadability and consistency the hardest was the pate with goose meat followed by pate with turkey meat and pate from chicken meat and liver and the softest was the pate with duck meat. The results from instrumental spreadability and hardness showed positive correlations with the results of the sensory analysis.

Food emulsions with amidated pectin from celery (Apium graveolens var. rapaceum D.C.) tubers

Iv. Petrova1, N. Petkova2*, M. Ognyanov3, Ap. Simitchiev4, M. Todorova2, P. Denev2

1Department of Catering and Tourism, Faculty of Economic, University of Food Technologies, 4002 Plovdiv, Bulgaria
2Department of Organic Chemistry and Inorganic Chemistry, Technological Faculty, University of Food Technologies, 4002 Plovdiv, Bulgaria 3Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Laboratory of Biologically Active Substances, 4000 Plovdiv, Bulgaria
4Department of Machinery for Food Industry, Technical Faculty, University of Food Technologies, 4002 Plovdiv, Bulgaria

(Manuscript received 29 May 2017; accepted for publication 22 August 2017)

Abstract. Hydrocolloids, especially polysaccharides from traditional plant sources and their derivatives possessed significant emulsifying properties. Pectin was isolated from celery tubers by accelerated “green” method for extraction based on ultrasonic irradiation. Further chemical modification of celery pectin was performed with 4 mol/L NH3. The amidated celery pectin was obtained with the following characteristics: the degree of esterification (DE) 31%, the degree of amidation (DA) 16%, degree of acetylation (DAc) 2% and anhydrouronic acid content (AUAC) 68%. This modified pectin was incorporated in preparation of model30,40and50%oil-in-wateremulsions.Theeffectofamidationofcelerypectinonthestabilityofemulsionswasinvestigated. Theresultsshowedthat amidation increased the emulsifying properties of pectic polysaccharides. It affected also the rheological characteristics of model emulsion. The current study demonstrated preparation of emulsion with low-caloric amidated pectin as proper alternative to the traditional emulsifiers.

Carcass characteristics and technological properties of Musculus Longissimus Lumborum at lambs from the Bulgarian dairy synthetic population and its F1 crosses with meat breeds

N. Ivanov1*, T. Angelova1, S. Laleva1, S. Ribarski2, D. Miteva1, D. Yordanova1, V. Karabashev1, I. Penchev2

1Agricultural Institute, 6000 Stara Zagora, Bulgaria
2Department of Morphology, Physiology and Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 28 March 2017; accepted for publication 26 May 2017)

Abstract. The purpose of this study is to determine the effects of the breed on some of the carcass characteristics and the technological properties of Musculus Longissimus Lumborum in lambs from the Bulgarian Dairy Synthetic Population and its F1 crosses with Ile de France and Mutton Charollais breeds. The scientific study took place at the Agricultural Institute of Stara Zagora, Bulgaria. Object of the study were lambs from the Bulgarian Dairy Synthetic Population and its crosses with Ile de France and Mutton Charollais breeds. The internal organs weight of the animals from the three groups was measured after their slaughter. In order to determine the meat/bones ratio, the left carcass halves were deboned. The eye muscle area and analyzed samples of Musculus Longissimus Lumborum was determined. The results show a slight variation in the weight of the internal organs of the animals from the three groups. The Mutton Charollais crosses come first in terms of eye muscle area (11.34 cm2), followed by the Ile de France crosses (11.21 cm2), and the lambs from the reference group come last with only 8.64 cm2 (P ≤ 0.001). With regard to the meat/bones ratio, it was found out that in the Ile de France crosses it is the highest (2.90:1), followed by the Mutton Charollais crosses (2.68:1), and the lambs from the reference group (2.43:1) where it is the lowest (P >0.05). Ile de France crosses exhibited statistically significantly higher meat tenderness (P ≤ 0.001) and water-holding capacity (WHC) (P ≤ 0.01), while Mutton Charollais crosses – considerably higher cooking losses (P ≤ 0.001) than control animals.

Exopolysaccharide influence on acid gel formation

K. Yoanidu1, P. Boyanova2*, P. Panayotov2

1Department Industrial Microbiology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 26 Acad. G. Bonchev, 1113 Sofia,

2Department of milk and milk products, Faculty of Technology, University of Food Technologies, 26 Maritza, 4000 Plovdiv, Bulgaria

(Manuscript received 12 February 2017; accepted for publication 16 April 2017)

Abstract. Turbidimetric monitoring of milk coagulation was conducted in situ. Milk gel was produced by acidification with the use of three strains of starter culture. These strains were characterized by various acidification rate and exopolysaccharides (EPS) production. The concentrations of EPS affect mostly the pH of gel formation (5.53 – low EPS – producing strain; 5.33 – medium EPS – producing strain; 5.46 – high EPS – producing strain) whereas the time of gel formation depends on the various rate of acidification of all three strains.