Maria Doneva

Prof. Dr. Maria Doneva

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Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2015 in Biotechnology in Animal Husbandry
Verified
Journal Article
Open access
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MDMaria Doneva
Maria Doneva
DMD. Miteva
D. Miteva
SDSvetla Maksimova Dyankova
Svetla Maksimova Dyankova
INI. Nacheva
I. Nacheva
PMPetya Metodieva
Petya Metodieva
KDK. Dimov
K. Dimov
The main subject of study is the effect the plant proteases bromelain and papain exert on turkey meat tenderness. Experiments are conducted with samples of raw meat in 3 different concentration levels of the enzyme solutions (50U/ml 100U/ml and 200 U/ml) and in 3 different time periods (duration) of treatment (24 h, 48 h, 72h). An increase in enzyme concentration and treatment duration results in a higher degree of protein hydrolysis in the turkey meat. The optimal conditions for hydrolysis with minimal loss of protein and highest retention of organoleptic qualities of the meat samples are established.

28 February 2024 in Applied Sciences
Verified
Journal Article
Open access
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SDSvetla Maksimova Dyankova
Svetla Maksimova Dyankova
MDMaria Doneva
Maria Doneva
Margarita TerziyskaMargarita Terziyska
Margarita Terziyska
PMPetya Metodieva
Petya Metodieva
INIliana Nacheva
Iliana Nacheva
Pumpkin seed cake, a byproduct of cold-pressed oil production, represents a food waste material with a great potential for valorization. The objective of the present study is to optimize the papain enzymatic hydrolysis process of pumpkin seed cold-pressed oil cake (CPC) to obtain protein hydrolysates with the highest antioxidant activity. Box–Behnken Response Surface Methodology (RSM) was used to optimize the simultaneous effects of an enzyme concentration of papain, a temperature, and a reaction time on the process of enzymatic hydrolysis on pumpkin seed cold-pressed oil cake (CPC). For these three input factors, different values are used—1, 2, and 3% for papain concentration, 20, 30, and 40 °C for temperature, and 60, 120, and 180 min for hydrolysis time. Thus, the design generated a total of 21 experimental runs. The aim is to obtain protein hydrolysates with the highest antioxidant activity. The responses DPPH and ABTS were calculated and the determined regression models were statistically analyzed and validated. The results revealed that optimal conditions included a papain concentration of 1.0%, a temperature of 40 °C, and a hydrolysis time of 60 min to retrieve the highest level of bioactive compounds.

1 January 2018 in Biotechnology in Animal Husbandry
Verified
Journal Article
Open access
PDF file
MDMaria Doneva
Maria Doneva
INIliana Nacheva
Iliana Nacheva
SDSvetla Maksimova Dyankova
Svetla Maksimova Dyankova
PMPetya Metodieva
Petya Metodieva
DMDaniela Miteva
Daniela Miteva
The purpose of this study is to assess the tenderizing effect of plant proteolytic enzymes upon raw rabbit meat. Tests are performed on rabbit meat samples treated with papain and two vegetal sources of natural proteases (extracts of kiwifruit and ginger root). Two variants of marinade solutions are prepared from each vegetable raw materials- 50% (w/w) and 100 % (w/w), with a duration of processing 2h, 24h, and 48h. Changes in the following physicochemical characteristics of meat have been observed: pH, water-holding capacity, cooking losses and quantity of free amino acids. Differences in values of these characteristics have been observed, both between control and test samples, as well as depending of treatment duration. For meat samples marinated with papain and ginger extracts, the water-holding capacity reached to 6.74 ? 0.04 % (papain), 5.58 ? 0.09 % (variant 1) and 6.80 ? 0.11 % (variant 2) after 48 hours treatment. In rabbit meat marinated with kiwifruit extracts, a significant increase in WHC was observed at 48 hours, 3.37 ? 0.07 (variant 3) and 6.84 ? 0.11 (variant 4). The test samples also have reduced cooking losses compared to control samples. In control samples, cooking loss is increased from 13.79% (2 h) to 20.78 % (48 h). SDS-PAGE of meat samples after 48 h of treatment shows a reduction in the intensity of actin and myosin bands in all variants with papain and vegetal extracts. Electrophoretic pattern of test samples depicts proteolysis and degradation of muscle proteins.

24 September 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
MDMaria Doneva
Maria Doneva
SDSvetla Maksimova Dyankova
Svetla Maksimova Dyankova
Margarita TerziyskaMargarita Terziyska
Margarita Terziyska
PMPetya Metodieva
Petya Metodieva
INIliana Nacheva
Iliana Nacheva
Hemp seed oil cake, a by-product of hemp seed oil extraction, is characterized by its high protein content and bioactive components, making it a valuable resource for the development of functional products through enzymatic hydrolysis. Hemp seed oil itself is renowned for its rich content of essential fatty acids, vitamins, and antioxidants, contributing to its widespread use in health and wellness products. Consequently, the residual cake presents significant potential for the food, pharmaceutical, and cosmetic industries as a source of high-quality protein ingredients. The optimization of enzymatic hydrolysis conditions is crucial for maximizing the efficiency and quality of the resulting protein hydrolysates. This study aims to optimize the hydrolysis process of hemp seed oil cake with bromelain, focusing on three key factors: enzyme concentration (E/S ratio), temperature, and time, to achieve hydrolysates with superior antioxidant activity. Response Surface Methodology (RSM) was applied using a Box–Behnken design to model and optimize the hydrolysis conditions. The experimental design involved three levels for each factor: 1%, 2%, and 3% for bromelain concentration; 20 °C, 30 °C, and 40 °C for temperature; and 60, 120, and 180 min for hydrolysis duration, resulting in 21 experimental runs. The antioxidant activity was assessed via DPPH and ABTS radical scavenging assays (%RSA), and the derived regression models were statistically analyzed and validated. The findings indicate that the optimal conditions for obtaining protein hydrolysates with the highest antioxidant activity are a bromelain concentration of 3.0%, a temperature of 40 °C, and a hydrolysis time of 60 min.

1 January 2016 in Agricultural Science and Technology
Verified
Journal Article
Closed access
SDSvetla Maksimova Dyankova
Svetla Maksimova Dyankova
MDMaria Doneva
Maria Doneva

1 June 2014
Verified
Conference Paper
Closed access
YTYancho Todorov
Yancho Todorov
MDMaria Doneva
Maria Doneva
PMPetya Metodieva
Petya Metodieva
INIliana Nacheva
Iliana Nacheva
This paper describes an applied approach using an Adaptive Neuro-Fuzzy Inference System to formulate the contents of novel diary functional food. In the development stage for a new functional food, it is required a careful balancing in the product ingredients in order to be achieved not only a healthily effect but an acceptable sensory properties. This imposes the solving of multiparametric task, how to select an optimal product composition in order to obtain a products with a great percent of consumer acceptability. Since, the main sensory characteristics of the products can be assessed by trained panelists and encoded by a numerical estimates, the task can be solved by a simple fuzzy input-output mapping, in order to conclude how each component of the product affects a selected sensory characteristic.