Antioxidative mechanisms of tea catechins in chicken meat systems

The potential of dried Ginkgo Biloba leaves as a novel ingredient in fermented beverages of enhanced flavour and antioxidant properties

Fermentation enhances the nutritional profile of foods and beverages like beer, wine, and fermented teas. Ginkgo biloba, long utilized for its health-enhancing properties, contains bioactive compounds like terpene trilactones and flavonoids, known for their antioxidant and neuroprotective effects. This study explores the feasibility of using dried Ginkgo biloba leaves in SCOBY-mediated fermentation to produce novel health-promoting beverages similar to kombucha. Infusions of dried Ginkgo biloba leaves with varying sugar concentrations are fermented over 21 days. Results showed that these beverages exhibited potent antioxidant properties, notably higher than tea-kombucha, attributed to increased polyphenol content. HPLC analysis identified significant levels of bioactive compounds such as catechin and apigenin. Sensory evaluation highlighted optimal acceptance of the seven-day fermented product. This research underscores the potential of Ginkgo biloba as a functional ingredient in fermented beverages, offering a healthier alternative to conventional soft drinks.

Assessment of functional efficacy of sheep plasma protein hydrolysates and their utilization in mutton sausage

The present study examines the bioactive potential of sheep plasma protein hydrolysates (SPPH) produced by in-vitro gastrointestinal digestion as antioxidants, antimicrobials, anti-obesity agents, and inhibitors of lipid oxidation in sausage to address the oxidative stability and shelf-life issues of mutton. The antioxidant and antimicrobial activities, indicate a positive relationship between the degree of hydrolysis and digestion duration. The study finds that SPPH has a potent inhibitory effect on pancreatic lipase and cholesterol esterase. It has higher oil holding capacity than sheep plasma protein, observed at one hour of hydrolysis time. SPPH exhibit an improved behavior in foaming properties along alkaline pH and digestion time while display lower emulsifying activity and stability with hydrolysis advancement. The SPPH act as a natural preservative in developing functional mutton sausage by inhibiting lipid-oxidation. This study showed that the recovery of SPPH can be a cost-effective and sustainable strategy for generating available ingredients for enhanced shelf-life of meat products.

Effect of Brewing Conditions on Antioxidant Properties of Ginkgo biloba Leaves Infusion

Due to the growing awareness of the importance of healthy eating in society, there is an increasing interest in the use of herbs and low-processed, natural products. Ginkgo biloba is a raw material with a high pro-health potential, which is related to the high content of antioxidant compounds. The aim of the study was to determine the relationship between the antioxidant activity of Ginkgo biloba leaf infusions and the weighted amount of leaves and brewing time. In addition, a sensory analysis of the infusions obtained was carried out. The innovation is to determine the migration of micro- and macroelements to the infusion prepared from Ginkgo biloba depending on the leaves' weight used and the brewing time. The research showed the dependence of the antioxidant activity of the infusions and the migration of microelements on the size of the dried material and the brewing time. In the publication, the main factors influencing the quality of infusions were analysed, their mutual correlations were determined, and combinations showing the highest antioxidant activity and, at the same time, the highest sensory acceptability were selected.

Evaluation of the Amazonian fruit Ambelania acida: Chemical and nutritional studies

Ambelania acida is native to the Amazon region, with few published studies of its fruits. We examined the proximate composition of its fruits, including minerals, fatty acids, volatile organic compounds (VOCs), as well as its antioxidant capacity. The protein contents (2.61%) of the pulp and seeds (13.6%) were higher than observed in other taxa of the family or in other tropical fruits. Peel and pulp showed high contents of potassium, calcium, and magnesium, and the potassium content in the pulp was 1125 mg/100 g. The peel had higher contents of total phenolics, tannins, and ortho-diphenols than the pulp, as well as better antioxidant activity as evidenced by 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), and Fe²⁺ chelating activity assays. GC-MS analyses identified 42 VOCs in the peel and pulp, with more than 90% being classified as terpenes. Eleven types of fatty acids were identified in the lipid fractions of the peel, pulp, and seeds. Linoleic acid, an essential fatty acid for humans, was the principal fatty acid in the edible portion of the fruit, therefore, evidencing its nutritionally significant profile for the fruits when considering the relationship among polyunsaturated, saturated, and monounsaturated fatty acids. The information gathered here indicates that this native fruit is a healthy food source and its cultivation and consumption should be stimulated.

A comparative study on feeding timing and additive types of broilers in a high-temperature environment

Antioxidants such as vitamin C (VC) and green tea extract (GTE) have been reported to have various antioxidant functions and are used as one of the nutritional approaches to alleviate heat stress (HS) in chickens. However, studies on the feeding timing that can produce optimal effects have not been reported. In this study, the stress-relieving effect of VC and GTE addition timing was investigated in high-temperature broiler chickens. A total of 880 1-d-old male chickens were used, and the treatments were as follows: no feed additives provided, CON; VC 250 mg/kg added from 1 d, VC1; GTE 600 mg/kg added from 1 d, GTE1; VC 250 mg/kg added from 22 d, VC22; GTE 600 mg/kg added from 22 d, GTE22. The HS environment was provided for 2 wk from the 22 d and was set at 33 ± 1 °C, 55 ± 10% for 24 h. Feed and water were provided ad libitum. Broiler production was similar in all treatments. In chicken meat quality, the addition of VC and GTE had an effect on meat color and pH (P < 0.05). In particular, GTE had a positive effect on the antioxidant capacity and quality preservation of breast meat (P < 0.05). In blood characteristics, GTE1 significantly lowered the level of total cholesterol, and VC1 affected AST and IgM (P < 0.05). Interestingly, the VC1 group had a positive effect on the maintenance and development of intestinal morphology, a lower rectal temperature, and showed to relieve stress. In conclusion, the addition of VC and GTE has been shown to alleviate the high-temperature stress of broilers, and in the case of VC in particular, feeding from 1 d appeared to alleviate stress more effectively. This study suggests that it is important to determine the appropriate timing of addition of functional substances in order to effectively reduce various stresses that occur in livestock rearing.

Chemical and nutritional characterization of Ambelania duckei (Apocynaceae) an unexplored fruit from the Amazon region

Ambelania duckei Markgr is a species of the Apocynaceae family, native to the Amazon region that is unexplored from a nutritional point of view and studied in relation to its chemical constituents. This work presents an unprecedented study of the proximate composition, lipid profile, a chromatographic analysis, and the antioxidant activity of extracts obtained from the pulp, peel and seeds of the fruit. The results showed that potassium, calcium, and magnesium stood out as the most abundant key minerals in the fruit peel and pulp, with an emphasis on the potassium present in the fruit pulp at 1750.0 mg/100 g. The peel had the highest content of total phenolics (374.86 mg/g), flavonoids (15.54 mg/g), tannins (27.45 mg/g) and O-diphenols (379.36 mg/g; 645.71 mg/g). The antioxidant activity (AA) was highest in the peel compared to the pulp in the DPPH, ABTS, and ORAC tests showing: IC₅₀ of 29.82; 43.67; and 407.13 µg/mL, respectively but a lower activity for the Fe²⁺ chelator. The analysis of the lipid fractions from the peel, pulp, and seeds of the A. duckei fruit resulted in 14 types of fatty acids. The major fatty acids found in the three parts of the fruit were oleic acid (peel, 22.52 %), palmitic acid (pulp, 17.34 %), and linoleic acid (seeds, 47.99 %). The lipid profile and nutritional aspects had a PUFA/SFA ratio (0.4-1.8) in the different parts of the A. duckei fruit; the atherogenic and thrombogenic indexes were higher in the peel (1.23) and pulp (0.62), respectively. The ratio between the hypocholesterolemic and hypercholesterolemic fatty acids (0.5 - 3.8) calculated for the fruit are within the desirable range for a nutritious food. The chromatographic analysis of the volatile organic compounds (VOCs) from the peel and pulp of the fruit, identified 74 VOCs, of which 60.9 % are related to terpenes, and emit notes such as cucumber, green, fatty, floral, and mint, due to the presence of substances with OAVs > 10, especially α-ionone, 1,8-cineole, 2,4-decadienal, and dodecanal. The analysis of the MS and MS/MS spectra of the chromatograms obtained by LC- QTOF-HRMS led to the identification of 26 compounds in the peel, seeds and pulp of A. duckei, such as fatty acids, phenolic acid, flavonoids, proanthocyanidins, alkaloids, and terpenoids. The results show that the pulp of A. duckei has potential as nourishing food and the nutritional and chemical aspects of the peel can be applied to commercial applications.

Ultrasonics as a tool for development of pine-needle extract loaded bee wax edible packaging for value addition of Himalayan cheese

In the present study, Himalayan cheese, kradi was coated with beeswax loaded with pine needle extract (PNE) to increase its shelf life and nutraceutical potential. PNE was extracted via ultrasonication and incorporated into beeswax at concentrations, 2:1, 1:1, and 2:3 (grams of beeswax to mL of PNE). The dispersion of PNE in the coatings was carried out using an ultrasonic probe at a frequency of 20 kHz for 15 min and at power rating of 500 W. The coatings were characterised using scanning electron microscopy, light microscopy, dynamic light scattering (DLS), fourier transmission infrared spectroscopy. DLS revealed a hydrodynamic diameter and zeta potential of 12.11 ± 0.41 µm and -19.32 ± 0.61 mV for coating loaded with highest concentration of PNE. The bioactivities of the coating including antioxidant, antidiabetic and antibacterial assays revealed significantly higher values with the increase in PNE concentration. Shelf life and sensory evaluation study including microbiological and sensory analysis revealed inhibition of mould growth and good score of texture and appearance with the increase in concentration of PNE. The study provides a future perspective for application of beeswax loaded PNE coatings in cheese industry.

Impact of frozen storage on oxidation changes of some components in goose meat

The objective of this study was to investigate the oxidation activity and lipid oxidation changes in breast (BM) and leg (LM) muscles from 17-wk-old female White Kołuda geese packaged in a vacuum, and stored in freezing conditions at −20°C. The geese were fed ad libitum during the experimental period (up to 17 wk) on the same complete feed. The samples of LM (n = 18) and BM (n = 18) from the right carcass were stored for 30, 90, 80, 270, and 365 d. Lipid oxidation was described by determining changes in: TBARS value expressing the amount of malondialdehyde (MDA), total antioxidant capacity (TAC) measured by DPPH and ABTS methods and total reduction potential (TRP) measured by FRAP method. Moreover, total heam pigments pigment (THP), relative concentration of myoglobin (Mb), oxymyoglobin (MbO₂), and metmyoglobin (MMb) were determined in this study. Time of storage affected the TAC, TRP, TBARS, and the color stability of BM and LM. The THP concentration and Mb proportion decrease gradually during the 365 d of frozen storage, while the relative concentration of MMb increase in BM and LM. It was noted that the shares of MMb in both analyzed types of muscles stored for 365 d did not exceed 0.4. This value is considered to be the limit, after which the meat takes on an intense gray-brown color not accepted by the consumer. The oxidation processes occurring during frozen storage caused an increase of TBARS and a decrease of DPPH^•, ABTS^•+, FRAP values in both kinds of muscles. The amounts of TBARS during frozen storage of muscles did not exceed 2.0 mg MDA/kg of meat. A higher value of TBARS than 2.0 causes a lack of acceptance by consumers of the flavor profile. Based on the results concerning changes in the heam pigments, as well as changes related to the oxidation of lipids, we cannot unequivocally state in which types of muscles the changes had a more intense course.

The Changes in Antioxidant Activity of Selected Flavonoids and Caffeine Depending on the Dosage and Form of Thiamine

Phenolic compounds and thiamine may serve as therapies against oxidative stress-related neurodegenerative diseases. However, it is important to note that these components show high instability under changing conditions. The study’s aim was to determine the impact of the thiamine concentration (hydrochloride—TH and pyrophosphate—TP; in the range 0.02 to 20 mg/100 g on the indices of the chelating properties and reducing power, and free radicals scavenging indices of EGCG, EGC, ECG and caffeine added from 0.04 to 6.0 mg/100 g. Our research confirmed that higher concentrations of TH and TP can exhibit significant activity against the test antioxidant indices of all components. When above 5.0 mg/100 g of thiamine was used, the radical scavenging abilities of the compound decreased in the following order: EGCG > ECG > EGC > caffeine. The highest correlation was found for the concentration of thiamine pyrophosphate to 20.0 mg/100 g and EGCG. Knowledge of the impact of factors associated with the concentration of both EGCG, EGC, ECG or caffeine and thiamine on their activity could carry weight in regulating the quality supplemented foods, especially of nutrition support for people of all ages were oral, enteral tube feeding and parenteral nutrition).

Direct acidification of requeijão cremoso model by lactobionic acid: physical, chemical and antimicrobial effects

Abstract

Lactobionic acid (LBA) shows singular properties (antioxidant and antimicrobial). However, few studies aim to test them in foods and confirm the actual occurrence of properties. The present study aims to apply LBA/lactic acid in the production of requeijão cremoso model in order to recognize some of the effects caused by the component as a food additive. The effects on the requeijão cremoso model were evaluated by the final properties of the product: water activity, rheological properties, antioxidant and antimicrobial capacity. Model of requeijão completely acidified with LBA showed the maximum antioxidant activity (88%). The results revealed a potential of application of LBA for microbial inhibition. All model produced presented pseudo plastic behaviour.

Graphic abstract

Electrochemical screening of genoprotective and antioxidative effectiveness of Origanum vulgare L. and its functionality in the prevention of neurodegenerative disorders

A new way of electrochemical DNA sensor using as a screening tool for the determination of phytochemicals with high genoprotective functionality is proposed. The biosensor's detection layer was prepared with double stranded deoxyribonucleic acid (ds DNA) that were subjected to oxidative stress induced by ^•OH radicals generated by Fenton reaction. The oxidized guanine derivative, 8-oxo-7,8-dihydro-2'-deoxyguanosine, was treated as an indicator of DNA oxidative damage. This derivative may cause mutation through its ability to pair with adenine. The abnormalities of DNA structure and DNA repair system are known to be directly related to progressive neurodegeneration. The present study showed that during oxidative stress, the 2.5% oregano extract protected guanine from undergoing oxidation to 8-oxoguanine. The results revealed that this genoprotective effectiveness can make oregano a very efficient protective barrier against oxidative stress. Due to these unique properties of oregano we propose the recipe of a functional bread with its addition. It was found that the functionality of the prepared bread was not limited to antioxidative activity but also is expressed in the inhibition of cholinesterases. These findings indicate that oregano can act as an important component in the therapeutic diet recommended in neurodegenerative disorders.

Functional Properties and Antioxidant Activity of Morus alba L. Leaves var. Zolwinska Wielkolistna (WML-P)-The Effect of Controlled Conditioning Process

This study evaluated the effect of adding a new step, termed conditioning, to the traditional processing of leaves from Morus alba var. zolwinska wielkolistna grown in Poland (WML-P). This step, modeled on tea leaves processing, was conducted in a controlled environment on a semi-technical scale. The primary goal was to evaluate the effect of the WML-P conditioning for 1–4 h at 32–35 °C on the content of bioactive compounds (total phenolics, phenolic acids, flavonols, 1-deoxynojirimycin) and antioxidant activity (radical scavenging against DPPH, antioxidant capacity, chelating activity and ferric reducing antioxidant potential) of the lyophilized extracts. For the first time WML-P extracts content was comprehensively characterized by assessing dietary fiber fractions, fatty acids, amino acids, macro- and microelements and chlorophyll content. Compared to the traditional process, adding the conditioning step to WML-P processing resulted in an increased total phenolics content, radical scavenging capacity, ability to quench 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) and iron-chelating ability in the lyophilized extracts. The beneficial effect depended on conditioning time. The highest flavonols and phenolic acids content were found after 2-h conditioning. We concluded that adding a 2-h conditioning step to traditional WML-P processing results in getting WML-P lyophilized extract with increased bioactive compounds content and high antioxidant activity.

Variability of Hordeum vulgare L. Cultivars in Yield, Antioxidant Potential, and Cholinesterase Inhibitory Activity

Barley (Hordeum vulgare L.) is an annual plant cultivated in spring or autumn. Currently, over 70% of the cultivated barley grains are utilized for preparing fodder, while the rest is used for the production of malt and cereals in the food industry. The purpose of the present work was to evaluate the content of bioactive compounds, antioxidant potential, and cholinesterase inhibitory effect of the aqueous extracts of juvenile barley leaves. It was found that the barley cultivars differed in their content of the determined phytochemicals as well as their antioxidant potential and cholinesterase-inhibitory activity. The water extracts of young barley leaves contained phenolic acids as well as quercetin, rutin, and kaempferitrin. The extracts showed a higher inhibitory effect on 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) than on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. Based on the aqueous extracts analyzed, we found that winter cultivars were characterized by the highest iron-chelating activity. Furthermore, barley extracts showed a stronger inhibitory effect against acetylcholinesterase compared to butyrylcholinesterase. The results of the present work indicated that barley cultivars differed in their germination process. Among the tested samples, the highest cholinesterase inhibitory activity was shown by the Basic variety.

The Effect of Thiamine Concentration on the Antioxidative Activity Indices in Tea Extracts

The aim of the study was to determine correlations between the concentration of thiamine in systems and indicators of the antioxidative activity of ethanol tea extracts in the presence of soybean oil. Variability of the thiamine form was assumed by comparison of the influence of thiamine hydrochloride or thiamine pyrophosphate and fermentation of ethanol tea extracts. The study provides practical knowledge about the antioxidative activity of ethanol tea extracts in products containing fat and thiamine. The study showed that all tea extracts exhibited higher antioxidative activity in the presence of thiamine amounts of 0.1 and 0.8 mg/100 g. The antioxidative activity of ethanol tea extracts was significantly reduced when the concentrations were higher than the natural level for foods (over 1.0 mg/100 g). The systems containing white tea extract were the most vulnerable, whereas those with black tea were the least vulnerable. The presence of thiamine pyrophosphate in the system was more strongly correlated with reduced activity of the extracts than the presence of thiamine hydrochloride.

Lipid oxidation and its implications to meat quality and human health

Lipid oxidation not only negatively influences the sensory characteristics but also the functional characteristics of meat. During the process, various primary and secondary by-products are formed depending upon the types of fatty acids, oxygen availability, and the presence of pro- and antioxidants. Some of the lipid oxidation products only influence the quality of meat but others are implicated to various diseases and human health. Therefore, prevention of lipid oxidation in meat is important for meat quality and for human health as well. The imbalance of oxidants and antioxidants that favors oxidants in the biological system is called oxidative stress in the body. Although the body is equipped with defense enzymes and antioxidant compounds, there are many sources of oxidants or free radicals that can destroy the oxidants/antioxidants balance. Therefore, supply of extra antioxidants through food can help maintaining the balance in favor of antioxidants and help preventing various diseases and malfunctions of our body.

Functional characterization of biopolymer based composite film: Incorporation of natural essential oils and antimicrobial agents

Rosemary (REO), mint essential oil (MEO), nisin and lactic acid were incorporated at 0.5% to develop a novel functional packaging film including chitosan pectin and starch polymers (0.75:1.5:0.75 w/w). Inclusion of REO and nisin significantly (p ≤ 0.05) improved water barrier properties (0.014 g.mm/m²24h), tensile strength (25.95 MPa) and thermal stability as compared to control. ATR-FTIR spectra and XRD pattern elucidated structural interaction between EO's and biocomposite films. Addition of REO of and nisin increased microsctructural heterogeneity and opacity (2.78). Incorporation of REO and nisin exhibited the highest inhibitory activity against all tested pathogenic strains (Bacillus subtilis, Escherichia coli, and Listeria monocytogenes). The antioxidant properties of biocomposite films were analyzed using reducing power, metal chelation, DPPH and ABTS radical scavenging assays, which enhanced significantly (p ≤ 0.05) with the addition of MEO and REO. This study validated that incorporation of natural additives in active biocomposite films offers promising functional ingredients for packaging materials for various food applications.

Proteomic changes in EHEC O157:H7 under catechin intervention

Catechin exhibits antimicrobial activity against various microorganisms, such as EHEC O157:H7. This study reports the bactericidal effect of catechin on EHEC O157:H7 in simulated human gastrointestinal environment and the underlying antibacterial mechanism. Bacteriostasis test results showed that the minimum bactericidal concentration of catechin for EHEC O157:H7 was 5 g/L. The bactericidal effect of catechin in the gastrointestinal juice became more significant with increased culture time, and catechin exhibited a synergistic effect with bile salt in inhibiting EHEC O157:H7. Changes in the profile of protein expression in EHEC O157:H7 in response to catechin intervention were investigated. Two-dimensional electrophoresis identified 34 proteins with significantly altered expression. A total of 2 and 12 proteins were upregulated and downregulated, respectively. However, 20 proteins disappeared. No new protein was expressed compared with the control. Hence, catechin intervention resulted in diverse changes in the expression of proteins associated with cell structure and genetic information processing. Catechin could cause the disappearance of certain proteins or the destruction of certain peptides. These processes lead to the inhibition of EHEC O157: H7 cells.

Effect of plant extracts on lipid and protein oxidation of mackerel (Scomber scombrus) mince during frozen storage

The effects of different plant extracts [green tea extract (GTE), grape seed extract (GSE), and pomegranate rind extract (PRE)] at a level of 100 ppm equivalent phenolics and butylated hydroxytoluene (BHT) on the changes in quality of fish (Scomber scombrus) mince during 6 months frozen storage at -18 ± 1 °C were investigated. During storage, significant oxidative reactions in both the lipids and proteins were observed with the increase in thiobarbituric acid reactive substances (TBARS) and carbonyls and decrease in sulphydryl groups and protein solubility. BHT and PRE effectively inhibited lipid oxidation as lower peroxide and TBARS values were observed. Moreover, antioxidants added to minced fish significantly reduced protein oxidation compared to control without any antioxidant. The minced fish containing PRE had lower carbonyl and higher sulphydryl contents, but no significant differences for carbonyl and sulphydry contents were observed among antioxidant sources. Protein solubility decreased with increase in storage period. The loss of protein solubility was higher in control samples than in antioxidant treated ones. Among antioxidant sources, PRE was an excellent antioxidant toward both lipid and protein oxidations. Therefore, it could be a potential source of natural antioxidants in minced fish during frozen storage.

Effect of catechins on fattening performance, meat quality, some antioxidant and blood parameters and fattening costs in Japanese quail (Coturnix coturnix japonica)

The aim of this study was to investigate the effect of dietary supplementation of green tea (Camellia sinensis) catechins in quail (Coturnix coturnix japonica). Quail were fed with a basal diet, and the treatment groups were fed on the basal diet with 1.25 or 2.50 g/kg catechin supplementation for 30 d. Fattening performance and meat quality of the quail were estimated. Serum total antioxidant status (TAS), plasma and liver malondialdehyde (MDA) and some serum biochemical parameters were measured. The results showed that catechin supplementation did not affect live weight, feed intake, feed conversion ratio, carcass weight, carcass dressing or the nutrient composition of breast and thigh meats. The water holding capacity (WHC) of breast meat was increased in the 2.50 g/kg catechin treatment. Catechin supplementation increased the serum TAS, but decreased plasma MDA and liver MDA concentration as well as serum glucose and total cholesterol levels. Serum triglyceride and total protein levels were not affected by catechin supplementation. In conclusion, catechins have effective antioxidant hypoglycaemic and hypocholesterolaemic properties, as well as having the potential to increase meat quality in fattening quail. On the other hand, catechin supplementation did not have any negative effect on the fattening performance, meat nutrient composition and fattening costs in fattening quail.

Polyphenolic extracts of cherry (Prunus cerasus L.) and blackcurrant (Ribes nigrum L.) leaves as natural preservatives in meat products

The objective of this study was to evaluate the possibility of using polyphenolic extracts from cherry and blackcurrant leaves as natural antimicrobial agents in meat products. The polyphenolic composition of the extracts was analyzed and their impact on the microbial quality, lipid oxidation, color, and sensory evaluation of pork sausages was studied. Polyphenolic extracts were obtained from leaves collected in September. The total polyphenolic content in sour cherry leaf extract was 1.5 times higher than that found in blackcurrant leaf extract. Analysis of the polyphenol profile of each extract revealed two major groups: phenolic acids and flavonoids, including epigallocatechin and glycosides of quercetin and kaempferol. After chilling the sausages for 14 and 28 days, the extracts caused significantly lower MDA generation, indicating an antioxidant effect. Color changes after 28 days of storage were perceptible in the case of all treatments, with and without polyphenols. The application of sour cherry and black currant leaf extracts increased the shelf life of vacuum-packed sausages. Both extracts enhanced the microbial quality of the pork sausages over 14 days of refrigerated storage. Sour cherry leaf polyphenols were more effective against almost all studied groups of microorganisms.

Molecular structure and anti-proliferative effect of galangin in HCT-116 cells: In vitro study

Galangin is a naturally occurring plant flavonoid with potential anticancer activity. In present work, the Becke three-parameter hybrid exchange functional method and the Lee-Yang-Parr correction functional methods were used to investigate the structural properties of galangin. The structure-activity relationship analysis has been performed to determine its antioxidant pharmacophore by using density functional theory method and quantum chemical calculations. The free radical scavenging activities of galangin were analyzed with the use of 2, 2-diphenyl-1-picrylhydrazyl and compared with Vitamin C as a control. Galangin decreased the cell proliferation rate in HCT-116 cells and showed concentration- and time-dependent response. Galangin significantly increase the inhibitory effect on HCT-116 clonogenicity and promotes cell cycle arrest at the G2/M or G1 phase, as confirmed by flow cytometry analysis.

Effect of Extraction Method on the Phenolic and Cyanogenic Glucoside Profile of Flaxseed Extracts and their Antioxidant Capacity

The application of flaxseed extracts as food ingredients is a subject of interest to food technologists and nutritionists. Therefore, the influence of the extraction method on the content and composition of beneficial compounds as well as anti-nutrients is important. In the study, the effects of two solvent extraction methods, aqueous and 60 % ethanolic, on phenolic and cyanogenic glucoside profiles of flaxseed extract were determined and compared. The impact of extracted phenolic compounds on the antioxidant capacity of the extracts was also investigated. Defatted meals from brown and golden flax varieties were used as extraction material. The ethanolic extraction was more selective for phenolics (100.8-131.7 mg g-1) than the aqueous one (11.5-15.7 mg g-1). However, the contribution of particular phenolic compounds to total phenolics was much more dependent on flax variety than extraction method. A strong relationship was observed between both radical scavenging and ferric reducing activity and the content of phenolics (particularly secoisolariciresinol diglucoside). The correlation between extract chelating ability and phenolics was moderate suggesting that other flaxseed compounds are involved in this activity. The extraction method strongly affected cyanogenic glucoside content of flaxseed extracts; the aqueous extraction caused 96 % reduction in cyanogenic glucoside content (0.56-0.62 mmol g-1) when compared to the content in defatted meal (9.1-11.6 mmol g-1). On the contrary, ethanolic extraction resulted in the high cyanogenic glucoside content in the extracts (71-89 mmol g-1). The results reveals that ethanolic extraction gives extracts rich in antioxidant lignans; aqueous extracts have lower antioxidant activity than ethanolic but cyanogenic glucosides are significantly reduced.

The quality and storage stability of chicken patties prepared with different additives

Purpose

– The purpose of the present study was to evaluate the effect of green tea extract, fig and red pepper on the quality characteristics of chicken patties during refrigerated storage.

Design/methodology/approach

– The study was designed to evaluate the effect of green tea extract, fig and red pepper on the storage quality parameters of chicken patties. The products were developed by incorporating optimum level of green tea extract (400 mg/kg), fig (4 per cent) and red pepper (10 per cent) separately and were aerobically packaged in low-density polyethylene pouches and assessed for various storage-quality parameters under refrigerated (4 ± 1°C) conditions for 21 days of storage. The products were evaluated for various physicochemical, microbiological and sensory parameters at regular intervals of 0, 7, 14 and 21 days.

Findings

– A significant (p < 0.05) effect of green tea extract, fig and red pepper was observed on the pH and TBARS (mg malonaldehyde/kg) values of the chicken patties. A significant (p < 0.05) effect was also observed on the microbiological characteristics as the products incorporated with green tea extract, fig and red pepper showed significantly (p < 0.05) lower values for total plate count, psychrophillic count and yeast and mould count during the period of storage. Coliforms were not detected throughout the period of storage. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the products incorporated with green tea extract, fig and red pepper.

Originality/value

– Green tea extract (400 mg/kg), fig (4 per cent) and red pepper (10 per cent) successfully improved the oxidative stability and storage quality of the products during refrigerated (4 ± 1°C) storage and may be commercially exploited to improve the storage quality of muscle foods without adversely affecting the sensory quality of the products.

Oxidative damage to poultry: from farm to fork

Poultry and poultry meat are particularly susceptible to oxidative reactions. Oxidation processes have been for decades the focus of animal and meat scientists owing to the negative impact of these reactions on animal growth, performance, and food quality. Lipid oxidation has been recognized a major threat to the quality of processed poultry products. The recent discoveries on the occurrence of protein oxidation in muscle foods have increased the scientific and technological interest in a topic that broadens the horizons of food biochemistry into innovative fields. Furthermore, in recent years we have witnessed a growing interest in consumers on the impact of diet and oxidation on health and aging. Hence, the general description of oxidative reactions as harmful phenomena goes beyond the actual impact on animal production and food quality and reaches the potential influence of oxidized foods on consumer health. Likewise, the current antioxidant strategies aim for the protection of the living tissues, the food systems, and a potential health benefit in the consumer upon ingestion. Along these lines, the application of phytochemicals and other microelements (Se, Cu) with antioxidant potential in the feeds or directly in the meat product are strategies of substantial significance. The present paper reviews in a concise manner the most relevant and novel aspects of the mechanisms and consequences of oxidative reactions in poultry and poultry meat, and describes current antioxidant strategies against these undesirable reactions.

Hydrolysates of sheep cheese whey as a source of bioactive peptides with antioxidant and angiotensin-converting enzyme inhibitory activities

Enzymatic proteolysis may be employed to release bioactive peptides, which have been investigated for potential benefits from both technological and human health perspectives. In this study, sheep cheese whey (SCW) was hydrolyzed with a protease preparation from Bacillus sp. P7, and the hydrolysates were evaluated for antioxidant and angiotensin I-converting enzyme (ACE)-inhibitory activities. Soluble protein and free amino acids increased during hydrolysis of SCW for up to 4h. Antioxidant activity of hydrolysates, evaluated by the 2,2'azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid radical scavenging method, increased 3.2-fold from 0 h (15.9%) to 6h of hydrolysis (51.3%). Maximum Fe(2+) chelation was reached in 3h hydrolysates, and the reducing power peaked at 1h of hydrolysis, representing 6.2 and 2.1-fold increase, respectively, when compared to that of non-hydrolyzed SCW. ACE inhibition by SCW (12%) was improved through hydrolysis, reaching maximal values (55% inhibition) in 4h, although 42% inhibition was already observed after 1h hydrolysis. The peptide LAFNPTQLEGQCHV, derived from β-lactoglobulin, was identified from 4-h hydrolysates. Such a biotechnological approach might be an interesting strategy for SCW processing, potentially contributing to the management and valorization of this abundant dairy byproduct.

Effect of boiling in water of barley and buckwheat groats on the antioxidant properties and dietary fiber composition

In recent years, there has been an ever-increasing interest in the research of polyphenols obtained from dietary sources, and their antioxidative properties. The purpose of this study was to determine the effect of boiling buckwheat and barley groats on the antioxidant properties and dietary fiber composition. Antioxidative properties were investigated using methyl linoleate model system, by assessing the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and metal chelating activity. The results were compared with butylated hydroxytoluene (BHT). Raw barley and buckwheat groats extracts showed higher DPPH scavenging ability compared to boiled barley and buckwheat groats extracts. Raw barley groats extract exhibited higher antioxidant activity than boiled groats extract in the methyl linoleate emulsion. Higher chelating ability in relation to Fe (II) ions was observed for boiled groats extracts as compared to raw groats extracts. BHT showed small antiradical activity and metal chelating activity, while showing higher antioxidative activity in emulsion system. The analysis of groats extracts using HPLC method showed the presence of rutin, catechin, quercetin, gallic, p-hydroxybenzoic, p-coumaric, o-coumaric, vanillic, sinapic, and ferulic acids. Differences in the content of dietary fiber and its fractions were observed in the examined products. The highest total dietary fiber content was detected in boiled buckwheat groats, while the lowest - in boiled barley groats. The scientific achievements of this research could help consumers to choose those cereal products available on the market, such as barley and buckwheat groats, which are a rich source of antioxidative compounds and dietary fiber.

Individual and combined effects of genistein and hesperidin supplementation on meat quality in meat-type broiler chickens

BACKGROUND

There is growing interest in improving the production and meat quality of farm animals through dietary supplementation with phytochemical (e.g. flavonoids)-rich plants and/or their extracts. This study was conducted to analyse the supplemental effects of two purified flavonoids (genistein and hesperidin) individually and in combination on the oxidative status, sensory score and quality of breast meat in meat-type broiler chickens.

RESULTS

A significant increase (P < 0.05) in meat colour (L* score) and pH was observed for the group supplemented with 20 mg kg(-1) genistein and hesperidin. Water-holding capacity was also improved significantly (P < 0.01) for all genistein- and hesperidin-treated groups, while the sensory quality of breast meat remained unaffected. Lipid oxidation of breast meat was reduced significantly (P < 0.01) at 0 and 15 days of refrigeration in a dose-dependent manner for all supplemented groups. Meanwhile, some treated groups showed improved (P < 0.05) body weight, feed/gain ratio and hot carcass weight.

CONCLUSION

Genistein and hesperidin supplementation to broilers improved meat quality in a dose-dependent fashion, with pronounced effects of combined treatment. The results indicated that purified flavonoids such as genistein and hesperidin could potentially be used as feed additives in broiler production to promote meat quality.