Effect of Various Phyto-extracts on Physico-chemical, Colour, and Oxidative Stability of Pork Frankfurters

Effect of Fenugreek (Trigonella foenum-graecum L.) Seed Extracts on the Structure of Myofibrillar Protein Oxidation in Duck Meat

The effect of fenugreek (Trigonella foenum-graecum L.) seed extracts (FSEs) on the structure of duck myofibrillar protein (MP) oxidation was researched via particle size, zeta potential, Fourier transform infrared (FTIR), fluorescence spectroscopy, SDS-PAGE, and scanning electron microscopy (SEM) in the Fenton oxidation system. FSE (0.3 mg/mL) could scavenge 58.79% of the hydroxyl radical and possessed good antioxidation. FSE could retard the oxidation of MP, and the carbonyl formation and total sulfhydryl loss of MP decreased by 42.00% and 105.94%, respectively, after 4.67% of FSE treatment. SDS-PAGE results showed that 0.67% and 2.67% of FSE decreased the strength of the myosin heavy chain (MHC) and actin bands of the oxidized MP, respectively. The FSE changed the secondary structures of the MP and promoted the unfolding of the MP structure and the transformation from α-helix to β-turn. When treated with 0.67% of FSE, the hydrophobicity of the MP declined by 26.14%, and solubility was improved by 37.21% compared with the oxidation group. After 0.67% of FSE treatment, the particle size and zeta potential of the MP returned to the level of the blank group. Scanning electron microscopy revealed that FSE improved the apparent morphology of the MP. Overall, FSE had positive effects on the antioxidation of the duck MP, and it could improve the structure and characteristics of the MP. It is hoped that FSE could be considered as a natural antioxidant to retard the oxidation of the MP in meat products.

Cellulose nanofiber-based multifunctional films integrated with carbon dots and anthocyanins from Brassica oleracea for active and intelligent food packaging applications

A new generation of carbon dot-based active and intelligent packaging films with UV blocking, antibacterial, and real-time sensing potentials was fabricated using Brassica oleracea (BO) extract. The cellulose nanofiber (CNF) was used to prepare the multifunctional intelligent nanocomposite film integrated with BO anthocyanins (BOA) and BO-biowaste-derived carbon dots (BO-CDs). The incorporation of 1.5 % BO-CD and 6 % BOA in the CNF matrix improved the physicochemical and UV blocking (>189 % increase) properties of the fabricated films. The synthesized BO-CD exhibits high fluorescence, UV absorption, antibacterial and antioxidant functions. It showed strong radical scavenging activity against ABTS (~90 %) and DPPH (~80 %) compared to the neat CNF film. Scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) have shown enhanced compatibility and elemental composition of the BO-CDs/BOA additives in the CNF-polymer matrix. Packaging tests showed that the prepared film worked efficiently and non-destructively and was able to monitor the freshness of minced pork, fish, and shrimp in real-time through a distinct visual change from red to colorless/yellow during storage at 25 °C for 48 h. Active and intelligent films developed based on CNF/BO-CDs/BOA are expected to be applied as multifunctional packaging materials that can indicate quality changes and extend the shelf life of packaged perishable foods.

Effects of Cyclocarya paliurus (Batal.) Extracts on Oxidative Stability and Sensory Quality in Meat Products (Frankfurters)

Oxidation is one of the most common causes of the deterioration of meat and meat products. At the same time, synthetic antioxidants are becoming less accepted by consumers due to the potential health hazards they might cause. Therefore, a new trend to substitute these synthetic antioxidants with natural antioxidants has emerged. This study adds flavonoid extracts from Cyclocarya paliurus (C. paliurus) as a natural antioxidant for meat products (Frankfurters). The results showed that flavonoid extracts from C. paliurus had strong antioxidant and antibacterial activity. This is proportional to concentration, and the addition of extracts could significantly (p < 0.05) delay the lipid oxidation in the samples. In addition, we did not observe hazardous effects on the samples’ pH and texture as a result of adding flavonoid extracts. We observed that flavonoid extracts from C. paliurus at concentrations of 0.06% and 0.12% did not affect the color and sensory evaluation of the samples. At a concentration of 0.18% and 0.24%, the flavonoid extracts had a negative impact on the color and sensory evaluation of the samples, likely due to the yellow-brown color of the extract itself. The findings showed that a low concentration of 0.12% flavonoid extracts from C. paliurus in meat products could effectively prevent lipid oxidation without affecting the sensory quality.

Inhibition of lipid and protein oxidation in raw ground pork by Terminalia arjuna fruit extract during refrigerated storage

OBJECTIVE

Terminalia arjuna plant, specially its leaves, bark, and roots, are widely used in traditional herbal medicine due to presence of bioactive components and being a rich source of natural antioxidants. But its fruit has not been used for any such purposes despite its potential to retard oxidation. Hence, the antioxidant potential of Arjuna fruit extract (AFE) in retarding lipid and protein oxidation of raw ground pork was evaluated during refrigerated storage for 9 days.

METHODS

The AFEs were prepared using different solvents viz. ethanol (EH), water, ethanol: water (60:40) and methanol:hot water (60:40). The AFEs were analysed for total phenolic content (TPC), 2, 2-diphenyl-1-picrylhydrazyl radical scavenging activity and reducing power. Water extract (WE) and ethanol-water extract (EH-WE) were selected and incorporated at 1.0% into freshly minced pork meat and compared with a synthetic antioxidant, in retarding lipid and protein oxidation during storage.

RESULTS

The TPC in AFEs using different solvents ranged from 11.04 to 16.53 mg gallic acid equivalents/g and extracts exhibited appreciable scavenging activity ranging from 50.02% to 58.62%. Arjuna extracts significantly (p<0.05) improved the colour score of meat samples by reducing the formation of metmyoglobin during storage. Both the AFEs (WE and EH-WE) significantly (p<0.05) lowered the thiobarbituric acid reactive substances value, peroxide formation and formation of protein carbonyls in raw pork than control sample during storage. Upon sensory evaluation of all samples, it was found that AFE treatment could prolong the storage period of meat samples, without influencing the colour and odour score, up to 6 days.

CONCLUSION

AFEs used at 1% improved the oxidative stability, colour and odour score and prolonged the refrigerated shelf life of ground pork up 6 days. Therefore, AFE could be explored as an alternative natural antioxidant in retarding lipid and protein oxidation in meat products.

Optimisation of extraction protocol for Carica papaya L. to obtain phenolic rich phyto-extract with prospective application in chevon emulsion system

The present study optimized the extraction protocol conditions to obtain the antioxidant-rich bioactive extracts from Carica papaya L. (Papaya) leaves. A Box and Behnken Design (BBD) consisting of three different extracting variables viz. extracting temperature (60-70 °C), time (10-20 min) and solvent concentration (55-65%) was used. Antioxidant efficacy was recorded by evaluating four responses viz. ABTS, DPPH, SASA and total phenolic contents. The optimized model predicted, solvent concentration of 60% with extraction time of 15 min and extracting temperature of 65 °C with bioactive-rich antioxidants having highest total phenolic activity. The efficacy of obtained bioactive-rich papaya leaves extracts (PLE) were subjected for in-vivo evaluation in chevon emulsion added with the level of T-1 (0.10%); T-2 (0.25%); T-3 (0.50%) and control (without extract) stored under refrigeration (4 ± 1 °C) for 9 days by evaluating various physicochemical, microbiological, sensory quality characteristics. The pH was significantly higher for control than all treatments and water activity (aw) showed decreasing trend throughout storage period. Oxidation efficiency values showed an increasing drift during storage period, irrespective of added level of PLE, showing lowest oxidation in samples treated with 0.5% PLE. Sensory panellists awarded comparatively higher scores to all PLE treatments than control. Microbiological quality of emulsion incorporated with different levels of papaya leaves extract successfully improved and was lower in 0.5% PLE treated samples. It was concluded that extraction of bioactive antioxidants from Carica papaya L. leaves improved by optimising extraction parameters using RSM. Carica papaya L. leaves extracts have proven prospects as natural anti-oxidants in chevon emulsion as a meat emulsion system.

Preservative potential of Tinospora cordifolia, a novel natural ingredient for improved lipid oxidative stability and storage quality of chevon sausages

Purpose

The purpose of this study was to assess the preservative potential of Tinospora cordifolia as a novel natural preservative in muscle foods.

Design/methodology/approach

Chevon sausages were used as a model system and were prepared by incorporating different levels of T. cordifolia, namely, T1 (0.25 per cent), T2 (0.50 per cent) and T3 (0.75 per cent), and assessed for lipid oxidative stability and storage quality under refrigerated (4 ± 10°C) conditions.

Findings

Lipid oxidative stability showed a significant improvement as the products incorporated with T. cordifolia exhibited significantly (p = 0.001) lower thiobarbituric acid reacting substances (mg malonaldehyde/kg) in comparison to control. A significant improvement was also observed in the microbial stability as T. cordifolia-incorporated products showed significantly lower values for total plate count (log cfu/g, p = 0.001), psychrophilic count (log cfu/g, p = 0.003), yeast and mould count (log cfu/g, p = 0.02) and free fatty acid (percentage of oleic acid, p = 0.01). Significantly higher scores were observed for various sensory parameters of the treated products during storage.

Originality/value

Tinospora cordifolia successfully improved the lipid oxidative and microbial stability of the model meat product and may be commercially exploited as a novel preservative in muscle foods.

Effect of Nigella sativa seed extract on lipid and protein oxidation in raw ground pork during refrigerated storage

Purpose

Black cumin (Nigella sativa L.) is well known for its strong, hot, peppery taste and has many nutritional, pharmaceutical and traditional therapeutic uses. The aim of this study was to investigate the antioxidant effect of different solvent extracts of black cumin seed to retard lipid and protein oxidation in raw ground pork meat during refrigerated storage (4 ± 1°C) for nine days.

Design/methodology/approach

Black cumin extracts (BCEs) were prepared using different solvents, namely, ethanol, water, ethanol:water (60:40) and methanol:hot water (60:40). Extracts were analysed for total phenolic content (TPC), 1,1 diphenyl-2-picrylhydrazil (DPPH) radical scavenging activity and reducing power. Based on the results, water extract (WE) and ethanol–water extract (EHWE) of black cumin were selected and incorporated at 1.5 per cent into freshly minced pork meat and compared with a synthetic antioxidant, butylated hydroxytoluene (BHT; 100 ppm), in retarding lipid and protein oxidation. Treated and control samples were aerobically packed in low-density polyethylene bags for analysis of various parameters (pH, colour and odour score, peroxide, lipid and protein oxidation) during nine-day refrigerated storage study.

Findings

Results showed that BCEs had a good amount of TPC (4.4-7.4 mg gallic acid equivalents/g) and also DPPH scavenging activities (33.96-44.23 per cent), with WE and EHWE extracts showing highest reducing power and promising antioxidant capacity. Hence, BCEs (WE and EHWE) incorporated at 1.5 per cent into freshly minced pork meat was tested, compared to BHT (100 ppm) and control samples, in retarding lipid and protein oxidation during storage. In BCE-treated samples, thiobarbituric acid reacting substances, free fatty acids, peroxide, formation of protein carbonyls and off-odour or rancid odour development were lower than control and values were comparable with BHT. Incorporation of BCE did not negatively affect the colour of ground pork.

Originality/value

BCEs (WE and EHWE) at 1.5 per cent inhibited protein and lipid oxidation and it could be exploited commercially as an effective alternative in retarding oxidative deterioration of meat products.

Asparagus racemosus

Purpose

This paper aims to explore the possibility of utilization of Asparagus racemosus as a novel natural preservative in meat products.

Design/methodology/approach

Chevon sausages were used as a study model and prepared by incorporating different levels of A. racemosus, namely, T1 (0.25 per cent), T2 (0.50 per cent) and T3 (0.75 per cent) and were vacuum packaged and assessed for various lipid oxidative stability and storage quality parameters under refrigerated (4  ±  1°C) conditions.

Findings

Significantly (p < 0.05) lower thiobarbituric acid reacting substances (mg malonaldehyde/kg) values were observed for the products containing A. racemosus in comparison to control indicating a significant effect on the lipid oxidative stability. The products containing A. racemosus also showed significantly (p < 0.05) lower values for various microbiological characteristics like total plate count (log cfu/g), psychrophilic count (log cfu/g), yeast and mould count (log cfu/g), anaerobic count (log cfu/g) and free fatty acid (% oleic acid) values indicating the antimicrobial and antifungal properties of A. racemosus. No significant (p > 0.05) effect was observed on the cooking yield and moisture content of the products. Significantly (p < 0.05) higher scores were observed for various sensory parameters of the products containing A. racemosus during the entire period of storage.

Originality/value

A. racemosus successfully improved the lipid oxidative stability and storage quality of the model meat product without compromising the sensorial characteristics and has a great potential as a novel natural preservative in muscle foods.

Response surface optimization of extraction protocols to obtain phenolic rich antioxidant from sea buckthorn and their potential application into model meat system

In the present study, processing parameters for the extraction of phenolic rich sea buckthorn seed (SBTE) extract were optimised using response surface method and subjected for in vitro efficacy viz. total phenolic, ABTS, DPPH and SASA activity. The optimised model depicted MeOH as a solvent at 60% concentration level with a reaction time of 20 min and extracting temperature of 55 °C for the highest yield and total phenolic content. The efficacy of different concentration of obtained SBT was evaluated in raw ground pork as a model meat system on the basis of various physico-chemical, microbiological, sensory quality characteristics. Addition of 0.3% SBTE significantly reduced the lipid peroxidation (PV, TBARS and FFA) and improved instrumental colour (L*, a*, b*) attributes of raw ground pork during refrigerated storage of 9 days. Results concluded that SBTE at 0.3% level can successfully improve the oxidative stability, microbial, sensory quality attributes in the meat model system.

Applications of Wine Pomace in the Food Industry: Approaches and Functions

Winemaking generates large amounts of wine pomace, also called grape pomace. This by-product has attracted the attention of food scientists and the food industry, due to its high content in nutrients and bioactive compounds. This review mainly focuses on the different published approaches to the use of wine pomace and its functions in the food industry. Traditionally, wine pomace has been used to obtain wine alcohol, food colorings, and grape seed oil. More recently, research has focused in the production of other value-added products, such as extracts of bioactive compounds, mainly phenols, recovery of tartaric acid, and the making of flours. The most common functions associated with wine pomace products are their use as antioxidants, followed by their use as fortifying, coloring, and antimicrobial agents. These products have mainly been applied to the preparation of meat and fish products and to, a lesser extent, cereal products.