Plant extracts as natural antioxidants in meat and meat products

Accumulation of Ascorbic Acid in Tomato Cell Culture: Influence of the Genotype, Source Explant and Time of In Vitro Cultivation

The production and commercialization of natural antioxidants is gaining increasing importance due to their wide range of biological effects and applications. In vitro cell culture is a valuable source of plant bioactive compounds, especially those highly dependent on environmental factors. Nonetheless, research on the accumulation in plant cultured cells of water-soluble antioxidant vitamins, such as the ascorbic acid (AsA), is very limited. Tomato fruits are a main dietary source of vitamin C and in this work, we explored the potential of in vitro cultured cells for AsA accumulation. Specifically, using a full factorial design, we examined the effect of the source explant, the time in tissue culture and the genetic difference present in two Introgression Line (IL7-3 and IL12-4) that harbor Quantitative Trait Loci (QTLs) for ascorbic acid in fruits. Moreover, we performed an expression analysis of genes involved in AsA metabolism to highlight the molecular mechanisms that can account for the difference between fruit explants and calli. Our work indicated that cultured tomato cells accumulate AsA well beyond the amount present in fruits and that the three factors under investigation and their interaction significantly influence AsA accumulation. The time in tissue culture is the main single factor and, different from the expectations for secondary metabolites, explants from unripe, mature green fruits provided the highest increase in AsA. Moreover, in controlled conditions the genetic differences between the ILs and the control genotype are less relevant for calli cultivated for longer time. Our work showed the potential of tomato cell culture to produce AsA and prompt further refinements towards its possible large-scale exploitation.

Dietary garcinol supplementation improves diarrhea and intestinal barrier function associated with its modulation of gut microbiota in weaned piglets

Background

The effects of dietary garcinol on diarrhea and intestinal barrier function associated with its modulation of gut microbiota in weaned piglets were investigated.

Method

One hundred forty four weaned piglets (Duroc × Yorkshire × Landrace) from 16 pens (9 piglets per pen) were randomly divided into four treatment groups: controls (CON) or those supplemented with 200 mg/kg (LOW), 400 mg/kg (MID), or 600 mg/kg (HIGH) diet garcinol. After 14-day trial, three piglets per pen were chosen to collect plasma, intestinal tissue and colonic digesta samples.

Results

We demonstrated for the first time that garcinol promoted growth performance, as increased average daily feed intake (ADFI) and decreased feed/gain ratio (F/G); and reduced diarrhea incidence (P < 0.05); and strengthened antioxidant capacity, as an increased antioxidative index (P < 0.05). Additionally, garcinol ameliorated intestinal barrier dysfunction, as an increased villus height to crypt depth ratio, increased zonula occludens protein 1 (ZO-1), occludin and claudin-1 expression in the jejunum and ileum (P < 0.05), and decreased intestinal permeability (P < 0.05); and reduced inflammation, as decreased cytokine interleukin (IL)-6, IL-10, IL-1β and tumor necrosis factor-α (TNF-α) levels in the mucosa of the jejunum and ileum, and NF-κB p65 translocation (P < 0.05). Moreover, garcinol inhibited the growth of most harmful bacteria in the gut, especially Escherichia coli, and increased the growth of the beneficial bacteria Lactobacillus.

Conclusion

This work provides a fundamental basis for the future development of garcinol-functional food use for improving diarrhea and intestinal barrier function in weaned piglets and for understanding the biological effects of garcinol and its potential as a functional feed additive.

Bilberry and Sea Buckthorn Leaves and Their Subcritical Water Extracts Prevent Lipid Oxidation in Meat Products

The aim of this study was to find new sustainable, Nordic natural antioxidant sources, develop subcritical water extraction (SWE) process for recovering the antioxidant compounds from the most potential raw materials, and to test their antioxidative effects in meat products. The antioxidant capacities of water and 50% ethanol (aq) extracts of 13 berry, grain, and horticultural plant materials as well as hexane/ethanol extracted stilbene fractions from pine heartwood and spruce inner bark were measured in hydrophilic and lipophilic systems. Tree, bilberry leaf (BL), and sea buckthorn leaf (SBL) extracts showed the highest antioxidant capacities. BL and SBL were selected for the development of SWE. The optimal conditions for recovering maximal antioxidative capacities were 110 °C/1 min for SBL and 120 °C/1 min for BL. Dried BL and SBL and the respective optimized subcritical water extracts were applied in chicken slices and pork sausage, and their ability to prevent lipid oxidation was evaluated during 8 and 20 days storage, respectively, at 6 °C. All tested plant ingredients effectively prevented lipid oxidation in the products compared to the control samples. Sensory acceptance of the plant ingredients was good, especially in the chicken product. To our knowledge, this is the first study to assess the antioxidant effects of SW extracted berry leaves in meat products.

Application of natural antioxidant extract from guava leaves (Psidium guajava L.) in fresh pork sausage

The current study was conducted to determine the antioxidant efficacy of guava leaf extract (3000 to 6000 ppm on fat basis) in fresh pork sausage, compared with negative control (CON) and 200 ppm butylated hydroxytoluene (BHT), for 0, 1, 4, 7, 10, and 14 d at 4 °C. The extract provided a total antioxidant capacity of 1505 μmol trolox equivalence/g. From d 4, the extract at 5000 and 6000 ppm provided greater (P < .05) antioxidant capacity than the CON and was either similar (P > .05) or greater (P < .05) than BHT. From d 4, the sausage formulated with 4000 to 6000 ppm of guava leaf extract had less conjugated dienes, lower peroxide and acidic values, less thiobarbituric reactive substances value, and better color (P < .05) than the CON and did not differ from BHT (P > .05). Guava leaf extract at 4000 ppm or greater is effective in preventing oxidation in fresh pork sausage.

Assessment of Pomegranate Juice as an Alternative “Substrate” for Probiotic Delivery. Recent Advances and Prospects

The probiotic products in the market are mostly milk-based products, such as yoghurts, cheese and fermented milk. However, lately, there has been an increasing demand for non-dairy probiotic products due to various reasons such as allergies, lactose intolerance, high cholesterol content and consumers turning to more natural foods. Fruit juices are considered as an appropriate new substrate for probiotic delivery. From these, pomegranate (Punica granatum L.) is gaining more attention in recent years. Pomegranate is a fruit known since ancient times for its therapeutic qualities, such as antioxidant, anti-inflammatory, antibacterial, antiviral and antitumor properties, among others. Pomegranate juice contains a range of bioactive compounds such as phytochemicals, like polyphenols, ellagitannins, anthocyanins and punicalagins. The fermentation of the juice with probiotic strains seems to provide beverages of high nutritional values and accepted organoleptic quality. Therefore, the aim of this comprehensive review is to present an overview of the innovative in vitro and in vivo assays that have taken place regarding fermentation of pomegranate juice by probiotic bacteria. In addition, various drawbacks are underlined and solutions are proposed and discussed regarding the feasibility of pomegranate juice as an alternative substrate for probiotic delivery.

Effect of lipophilic sea buckthorn extract on cream cheese properties

The aim of this study was to evaluate the physico-chemical, microbiological, sensory properties and antioxidant activity of the functional cream cheese prepared with lipophilic extracts of sea buckthorn (Hippophae rhamnoides L.). The first step of the research consisted of an evaluation of the physico-chemical characteristics and the antioxidant capacity of the sea buckthorn lipophilic extracts. The sea buckthorn extracts had a significant antioxidant capacity (67.04 ± 2.67%), a content of total carotenoids of 8.27 ± 0.01 mg L-1 and a content of total polyphenols of 1842.86 ± 1.41 mg/100 g dry vegetal material. The addition of the sea buckthorn extracts did not negatively affect the fresh cream cheese's sensory characteristics. The addition of sea buckthorn extracts to the cream cheese resulted in an increase of antiradical activity and dry matter content, a decrease in acidity and higher growth inhibitition of germs.

Effect of Date (Phoenix dactylifera L.) Pits on the Shelf Life of Beef Burgers

A new ingredient from date palm coproducts (pits) was obtained and tested as a preservative in burgers. Different concentrations of date pit (0%, 1.5%, 3%, and 6%) were added to beef burgers, and its effect on the safety and quality was evaluated during 10 days of storage. The incorporation of date pit was able to improve the shelf life and the cooking properties of the burgers. The date pit stabilized the color, lipid oxidation, and microbial growth of the burgers during the storage time due to the antioxidant activity and the phytochemical content of the date pits. For the consumer panel, the color and the off-odors were improved, and the addition of 1.5% and 3% date pit in cooked burgers obtained similar scores. Based on the obtained results, the new ingredient from date pit may have potential preservative properties for enhancing stability during shelf life and could improve the composition of bioactive compounds (fiber and phenolic content) of beef burgers.

Influence of sodium tripolyphosphate coupled with (−)-epigallocatechin on the in vitro digestibility and emulsion gel properties of myofibrillar protein under oxidative stress

This work demonstrates the effects of STP coupled with EGC on the formation of the MP emulsion gel under oxidative stress.

Substitution of synthetic antioxidant by curcumin microcrystals in mortadella formulations

This research was to compare mortadella elaborated with synthetic antioxidant and microcrystals of curcumin in relation to its physicochemical and sensorial characteristics for a period of 90 days. It was detect no differences between the three evaluated treatments in relation to the pH, color, and texture profile features. The mortadella with curcumin microcrystals showed significantly lower TBARS values at the end of the storage when compared to the other treatments. In the sensory analysis, the addition of curcumin decreased the acceptance of color's sample and the purchase intention, but no significant difference was observed among the other attributes. The color of the sample containing curcumin also became worse than its day-of-production standard during storage. The results obtained suggest the potential of curcumin in replacing synthetic antioxidants in cooked meat sausage, since it practically does not modify its physicochemical characteristics, besides preventing the oxidation of the food.

The Effect of Natural Antioxidants on Quality and Shelf Life of Beef and Beef Products

Oxidation processes are the major cause of deterioration of meat quality and shelf life of meat products, leading to negative changes in nutritive value and in sensory and physicochemical properties of meat. Until now, the synthetic antioxidants like butylated hydroxyl anisole have been commonly used to prevent oxidation, which however may cause potential human health risks and increase toxicity of the product. However, natural antioxidants can be the alternative solution for this problem since plants and plant materials are rich in bioactive compounds (as natural antioxidants) with potential health beneficial effects. Moreover, the interest of consumers in using natural products is still increasing. There is an expectation of replacing synthetic antioxidants and preservatives by natural ones. Therefore, the aim of the present review is to provide information on the effect of natural antioxidants from vegetables and fruits like olives, pomegranate or grapes, and herbs and spices like rosemary, oregano, sage, black cumin or turmeric, rich in bioactive compounds on quality and shelf life of beef and beef products.

Effects of encapsulated rosemary extract on oxidative and microbiological stability of beef meat during refrigerated storage

In this study, the effect of rosemary extract in two free and encapsulated forms to increase the shelf life of beef meat during a 28-day refrigerated storage period was investigated. For this purpose, rosemary was extracted using different extraction methods including ultrasound, solvent, and supercritical fluid extraction. The amount of phenolic compounds, antioxidant properties (free radical scavenging capacity of DPPH radical, ferric reducing antioxidant power), and antimicrobial activity of rosemary extract against pathogenic bacteria were evaluated. According to the results, the highest amount of phenolic compounds, antioxidant, and antimicrobial activity was observed in rosemary extracted by ultrasound method that used for next study (p < .05). In order to encapsulation of the rosemary extract, basil seed gum and soybean protein isolate separately and in combination form (1:1 w:w ratio) were used as carriers. Based on the particle size, zeta potential, and encapsulation efficiency tests, the best carriers were soybean protein isolate that used as a carrier for encapsulation. Then, to investigate the effect of rosemary extract to increase the shelf life of beef meat, 5 treatments including control, rosemary extract with concentrations of 800 ppm and 1,600 ppm, and nano-capsulation form of it with 800 ppm and 1,600 ppm concentrations were selected and they were periodically evaluated for chemical and microbial analysis (peroxide value, Thiobarbituric acid, color index, pH, and total viable count). The results showed that rosemary extract has an antimicrobial and antioxidant properties which could increasingly delay microbial spoilage and lipid oxidation of beef meat fillets, nano-capsulation form of rosemary could increase these qualities. The best results were observed in nano-capsulation of rosemary extract with 1,600 ppm (p < .05) as well as increased the shelf life of fillets till 21st day. Therefore, it seems that encapsulated rosemary extract could be used as a natural preservative in beef meat and meat products.

Effect of Cacao Nip Extracts (CEs) on Quality Characteristics of Pork Patties during Cold Storage Period

Cacao has been shown to have antioxidant effects and health benefits. However, the applicability of cacao as a meat preservative has not been thoroughly evaluated. Here, we examined the effects of cacao nib extracts (CEs) on suppression of fat oxidation and enhancement of quality characteristics of pork patties. Cacao nib powder was extracted in distilled water or 50%, 70%, or 99% ethanol. CEs prepared using 70% ethanol had the highest total phenolic and total flavonoid contents, and the highest 1,1-diphenyl-2-picrylhytdrazyl radical and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities. Decompression-concentrated CEs prepared using 70% ethanol and 0.1% ascorbic acid were added to pork patties, and the physiochemical properties of the patties were measured. The pH of all pork patties increased during storage, but tended to decrease according to the CEs content. CEs enhanced the preservation of redness and texture of the pork patties during storage. Analysis of thiobarbituric acid reactive substances (TBARS) in patties revealed that fat oxidation was highly suppressed in all treatment groups containing CEs during storage, and TBARS values decreased according to CE content. Treatment with 0.1% CE reduced fat oxidation to a level similar to that of treatment with 0.1% ascorbic acid. Consumer flavor preference increased according to CE content, and overall preference was the highest for patties prepared with 0.05% and 0.075% CEs. Overall, 70% ethanol was found to be the optimal concentration for extraction of cacao nibs, and adding 0.05% or 0.075% CEs to pork patties yielded the highest quality.

Antioxidants of Natural Plant Origins: From Sources to Food Industry Applications

In recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatings.

Plant-Derived Extracts Feed-Addition and Packaging Type Influence Consumer Sensory Perception of Pork

This paper investigates whether the combination of the addition of extracts derived from plants (plants derived extracts, PDE) to pork feedstuff and the meat conservation conditions (packaging and time exposure) affect consumers' perception of pork quality, studied by means of visual appraisal, purchase intention and a home test. The three PDE groups were control, garlic extract and blended oil composed by carvacrol, timol, cynamic aldehide and eugenol extracts. Meat was packed in film, vacuum or modified atmosphere (MAP) packaging. A visual test was designed comprising a four-day storage step followed by a four-day exposure step in a refrigerated island display case. All studied effects influenced visual appraisal scores, being time exposure and packaging effects more noticeable than PDE or pig-sex effects. Meat from MAP scored higher than the rest. Scores decreased as exposure time increased, but this evolution was less perceptible in vacuum packaging and was faster for meat from the garlic group. Only gender affected the visual appraisal scores, with women scoring higher than men. Neither PDE addition nor pig sex affected to purchase intention whereas both exposure time and packaging type did. A maximum of 2 days of exposure would be recommended. In the home-test, meat from male pigs obtained higher scores than meat from female pigs, and none of the consumer-related effects influenced the given scores.

Banana inflorescences: A cheap raw material with great potential to be used as a natural antioxidant in meat products

The bioactive compounds and the antioxidant activity of extracts made with various parts of banana inflorescences (bracts, male flowers, rachis, and whole inflorescence) were evaluated in the first part of this study. The extract made with male flowers (EMF) had a higher content of phenolics and flavonoids, lower IC₅₀ value, and higher FRAP value. Thus, EMF was selected to be used in sausage formulations at the concentrations of 0, 0.5, 1, 1.5, and 2%. The effect of this reformulation on the physicochemical, oxidative, and sensory characteristics of the sausages was evaluated during the refrigerated storage (28 days). EMF presented an effective antioxidant activity, with no major changes on pH, aw, and color parameters. In addition, the sensory quality of the product was not affected by the addition of up to 2% EMF. Therefore, EMF has great potential to be used as a natural antioxidant in meat products.

Dietary Supplementation of Tannin-Extracts to Lambs: Effects on Meat Fatty Acids Composition and Stability and on Microbial Characteristics

Two extracts derived from plant material rich in hydrolysable (Tara, T; Caesalpinia spinosa) or condensed (Mimosa, M; Acacia mearnsii) tannins were added to lamb's diet and their effects on meat quality and on microbial population were evaluated; a diet without tannins represented the Control (C). Meat pH, vitamin E, intramuscular fat content and muscle fatty acid composition were determined. Oxidative stability and microbiological analyses were performed on meat samples after 0, 4 and 7 days of refrigerated storage. Psychrotrophic bacteria were identified through MALDI-TOF MS analysis. Regarding meat fatty acids, Tara treatment decreased the percentage of monounsaturated fatty acids. The counts of all microbial groups were similar among dietary treatments at day 0, while a significant reduction of microbial loads was observed in T-group at day 7. Pseudomonas fluorescens group count was significantly affected by T extract supplementation. The MALDI-TOF MS identification revealed the dominance of Pseudomonas fragi species in all samples while Pseudomonas lundensis, Brochothrix thermosphacta and Candida famata were revealed only in control ones. In conclusions, the tannin extract supplementation is a promising dietary strategy to preserve lamb meat quality.

Comparison of Butylated Hydroxytoluene, Ascorbic Acid, and Clove Extract as Antioxidants in Fresh Beef Patties at Refrigerated Storage

This study was performed to assess the comparison of the effects amongst butylated hydroxytoluene (BHT), clove extract (CE), and ascorbic acid (AA) as antioxidants on the oxidative stability and color values in fresh beef patties. The adding of BHT, AA, and CE to patties significantly restrained lipid oxidation, lowered hue angle as color value, and expanded redness and chroma values of fresh beef patties in comparison to the control (p<0.05). BHT and AA significantly led to impede the protein oxidation of patties by lowering carbonyl content (p<0.05). CE had no negative effect on protein oxidation. The antioxidant effects of BHT, AA, and CE were obviously manifested. Nonetheless, BHT, AA, and CE appeared to have insignificant difference of each other for lowering the protein oxidation at the end of storage. BHT and CE represented lowered lipid oxidation in comparison to AA. The antioxidant effects of BHT, AA, and CE on lipid oxidation were more marked than the effects on protein oxidation. Furthermore, CE as a natural antioxidant evinced the efficiency in oxidative stability and color stability in fresh beef patties. The study implied that CE could substitute the use of BHT and AA when making beef patties during storage.

Antioxidant Effect of Extracts from Native Chilean Plants on the Lipoperoxidation and Protein Oxidation of Bovine Muscle

The present study investigated the antioxidant potential and the ability to inhibit lipid and protein oxidation in bovine meat of four native Chilean species: canelo (Drimys winteri), nalca (Gunnera tinctoria), tiaca (Caldcluvia paniculata), and ulmo (Eucryphia cordifolia). Phenolic acids (gallic, chlorogenic, caffeic, and coumaric) and flavonoids (catechin, epicatechin, and rutin) were identified and quantified by HPLC-MS/MS. Drimys winteri extract exhibited the highest antioxidant capacity evaluated by oxygen radical absorption capacity-red pyrogallol method (ORAC-PGR) and ferric ion reducing antioxidant power (FRAP) assays. All extracts decreased lipid oxidation induced by 2,2’-azo-bis(2-amidinopropane) dihydrochloride (AAPH) derived peroxyl radicals by anywhere between 30% and 50% the. In addition, canelo and nalca extracts decreased spontaneous oxidation by around 57% and 37% in relation to the control group, being even more efficient than butylated hydroxyanisole (BHT) a synthetic antioxidant. Protein oxidation in the myofibrillar proteins was evaluated by the formation of protein carbonyls and loss of protein thiols. The canelo, ulmo, and nalca extracts decreased the formation of carbonyls by around 30%. Plant extracts and BHT did not show an antioxidant effect on protein thiol loss. However, tiaca and ulmo extracts exerted a pro-oxidant effect, favoring the oxidation of sulfhydryl groups. The oxidizing system induced structural changes in myofibrillar protein (SDS−PAGE). A protective effect on protein structure from the canelo extract can be observed during the incubation when compared to samples incubated with AAPH.

The antioxidant effectiveness of liquorice (Glycyrrhiza glabra L.) extract administered as dietary supplementation and/or as a burger additive in rabbit meat

The present research studied the effect of liquorice extract (in feed and/or directly in burgers) on the shelf-life of rabbit meat. Before weaning, 28 individually caged rabbit does with their litters were divided in two dietary groups: Control, receiving a commercial diet, and Liquorice, receiving the Control diet supplemented with 6 g liquorice extract/kg (L). At 12 weeks of age, 15 fattened rabbits/treatment (one rabbit/cage) were slaughtered and their hindlegs dissected. Hindleg meat was trimmed, individually minced and divided into two parts: one of them was mixed with 0.25% (w/w) L. Storage time significantly reduced the amount of polyunsaturated fatty acids in the burger, to a different magnitude depending on the unsaturation level, experimental group and storage time. The α-tocopherol content showed higher levels during storage in the burgers from the Liquorice group. Also TBARs values showed a significant positive effect of dietary liquorice and a progressive increase at days 3 and 6 of storage.

Effect of Neem (Azadirachta indica L.) on Lipid Oxidation in Raw Chilled Beef Patties

The aim of this study was to determine the total polyphenol content, radical scavenging and antimicrobial activities of Azadirachta indica (A. indica) and to evaluate their effect on shelf-life stability of raw beef patties during refrigerated storage at 4 ± 1 °C. During 11 days of storage, the antioxidant effect of A. indica on ground beef meat was investigated by the determination of lipid oxidation, pH, anti-radical activity, color, hexanal content, and microbial growth. The results obtained showed that fresh A. indica leaves and synthetic conservative behaved in the same way and retarded the lipid oxidation of chilled beef patties while increasing their pH (5.40 and 5.45, respectively). It can also be said that A. indica limited the loss of color, reduced the metmyoglobin formation (36.70%) and had a significant effect on bacterial growth and hexanal content. In addition, the results obtained through anti-radical and antimicrobial properties showed proportional values of total polyphenol content and radical scavenging activity of leaf extracts as they showed their antimicrobial effect against some bacteria such as Staphylococcus aureus and Micrococcus luteus, among others. These results support the involvement of A. indica in the food industry as a natural antioxidant that could replace synthetic ones.

The effects of dietary quercetin supplementation on the meat quality and volatile profile of rabbit meat during chilled storage

Thirty-four New Zealand White rabbits of both sexes were fed a control or supplemented (2 g/kg quercetin dihydrate) diet from weaning until slaughter (13 weeks). After post-mortem chilling, excised and minced Longissimus thoracis et lumborum muscles were stored at 3.2 °C under oxygen-permeable wrapping for 1, 3 or 5 days. Colour, pH, lipid oxidation (TBARS), antioxidant capacity (FRAP), volatile profile (day 1 and 5) and microbial count (day 5) were determined. Quercetin reduced alkane (day 5) and hexanal (day 1) concentrations, but otherwise had minimal antioxidant effect, and did not benefit microbial quality, and thus did not substantially improve the shelf-life. The sex effect was similarly limited. Overall, the pH increased and FRAP decreased during storage, but TBARS did not change and discolouration seemed delayed. The volatile profile was dominated by esters, alcohols and heterocyclic compounds, and while it changed during storage, lipid oxidation products did not increase as expected, suggesting that rabbit meat may have relatively active reducing mechanisms.

Effect of Tea Polyphenols on the Oxidation and Color Stability of Porcine Hemoglobin

The oxidation and color stability of porcine hemoglobin (Hb) in the presence of tea polyphenols (TP), as well as the mechanism, were investigated using the methods of color and oxidation analyses, ultraviolet-visible and fluorescence spectroscopy. Results indicated that TP interacted with the tryptophan and tyrosine residues of Hb through inserting into its hydrophobic pocket. This interaction showed a concentration-dependent effect on Hb, which might lead to completely opposite results. The presence of TP (16 mg/L) disrupted Hb (16 mg/L) structure, and the exposure of heme iron facilitated the oxidation and discoloration of Hb. However, a lower level of TP should not break Hb structure but could work as an antioxidant and restrain the formation of methemoglobin. Consequently, TP (1.6 mg/L) considerably maintained the redness of Hb (16 mg/L, P < 0.05) when stored at pH 7.4 and 25 °C for 72 hr. Results may provide scientific information for the proper use of TP in blood and meat products. PRACTICAL APPLICATION: Proper utilization of tea polyphenols (TP) in food products is beneficial to improve antioxidant capacity and nutrition quality of food. We proved that it was potential to corporate TP into blood and meat products to prevent discoloration and oxidative deterioration.

Antioxidant efficiency and mechanisms of green tea, rosemary or maté extracts in porcine Longissimus dorsi subjected to iron-induced oxidative stress

Plant extracts from rosemary (RE), green tea (GTE), and maté (ME) were compared for the protection against iron-induced oxidation in porcine homogenates at total phenolic concentrations from 25 to 250 ppm. Lipid oxidation as indicated by TBARS was in all cases sufficiently suppressed, especially for RE. Hydrophobic RE retarded overall oxidation in the homogenates with an inverted dose-dependent response. Optimum delay of oxygen consumption was found at the lowest concentration applied, similar to protection against thiols and formation of protein radicals as measured by ESR, whereas the high concentration increased oxygen consumption and caused additionally thiol loss possibly due to thiol-quinone interactions, generating protein-phenol complexes. Hydrophilic ME or GTE increased the initial oxygen consumption rate as an indication of prooxidant activities at elevated concentrations. However, they were found to protect myoglobin and protein at those high concentrations with GTE being more efficient, possibly due to better chelation effect.

Enterocin BacFL31 from a Safety Enterococcus faecium FL31: Natural Preservative Agent Used Alone and in Combination with Aqueous Peel Onion (Allium cepa) Extract in Ground Beef Meat Storage

Safety aspects and probiotic properties of Enterococcus faecium FL31 strain producing an enterocin, named BacFL31 were previously demonstrated. Taking into account its originality, the enterocin BacFL31 was added alone at 200 AU/g or in combination with the aqueous peel onion (Allium cepa) extract (APOE) at 1.56 ± 0.3 mg/mL to ground beef meat. Its biopreservative effect was evaluated by microbiological, physicochemical and sensory analyses during 14 days at 4°C. The APOE was characterized for its phytochemical content: total phenolic (TPC), flavonoids (TFC) and tannins contents (TAC), its antioxidant capacity using the in vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH) and its antilisterial activity. APOE had a high TPC, TFC and TAC respectively with 140 ± 2.05 (mg GAE/g), 35 ± 0.5 (mg QE/g) and 20.6 ± 1.4 (mg CE/g). Equally, APOE showed a potential radical scavenging activity compared to the butylated hydroxytoluene (BHT), with an anti-radical power (ARP) of 46 ± 1.5. During 14 days of storage at 4°C, the combination between APOE and BacFL31 limited the microbial deterioration (P < 0.05), led to a decrease in thiobarbituric acid reactive substances (TBARS) values and slowed down the metmyoglobin (MetMb) and carbonyl group accumulation and delayed the disappearance of sulfphydryl proteins (P < 0.05). The combination was also efficient (P < 0.05) against microflora proliferation, decreased primary and secondary lipid oxidation (P < 0.05), reduced protein oxidation and enhanced significantly (P < 0.05) the sensory attributes. Thus, the enterocin BacFL31 use from a safe Enterococcus faecium combined with APOE as a potential natural preservative to biocontrol ground beef was promising as it was effective at low concentration. The data lay bases for new tests to be carried out in other food matrices.

Effects of different antioxidants on quality of beef patties from steers fed low-moisture distillers grains

This research evaluated the effects of different antioxidants on overall quality of beef patties from steers fed distillers grains. Crossbred steers (n = 24) were fed corn, 40% Dry distillers grains plus solubles, or 40% modified distillers grains plus solubles - Dry Matter basis). Patties were made from ground chuck of individual animals and 4 antioxidant treatments were evaluated (CONTROL - no antioxidant, 0.3% ROSEMARY, 0.25% ACEROLA, and 0.6% CITRUS). Diets minimally affected quality attributes. Patties treated with ROSEMARY were shown significant lighter in color than other treatments on day 6. Patties treated with CITRUS were the reddest on days 5 and 6 of display. ACEROLA and CITRUS provided better lipid stability during display when compared to CONTROL and ROSEMARY. Treatment CITRUS reduced APC growth by 2 log when compared to all other treatments (P < 0.01). Although patties treated with CITRUS had higher off-flavor intensity, no effect was observed for overall desirability. Patties treated with 0.6% of CITRUS provided optimal overall quality.

Natural antioxidants of plant origin

Interest in the content of natural antioxidants in plant-based foods can be from the human health perspective, in terms of how these compounds might help promote one's health and wellness, or from the storage point-of-view, as the endogenous antioxidant constituents aid to extend a foodstuff's shelf-life. This chapter reports essential information about the mechanism of antioxidant action and methods employed for determination of their activity, classes of phenolic compounds (phenolic acids, flavonoids, lignans, stilbenes, tannins), sources of plant antioxidants (oil seeds, cereals, legumes, plants of the Lamiaceae family, tea and coffee, tree nuts, fruits, and berries), extraction strategies of phenolic compounds from plant material, and the influence of processing and storage on the content of natural antioxidants in foods and their antioxidant activity. Thermal processing, if not releasing bound phenolics from the structural matrices of the food, tends to decrease the antioxidant potential or, in the best case scenario, has no significant negative impact. Gentler sterilization processes such as high-pressure processing tend to better retain the antioxidant potential of a foodstuff than thermal treatments such as steaming, boiling, or frying. The impact of processing can be assessed by determining the antioxidant potential of foodstuffs either at the point of formulation or after different periods of storage under specified conditions.

Can innovations in traditional pork products help thriving EU untapped pig breeds? A non-hypothetical discrete choice experiment with hedonic evaluation

The EU is supporting measures that stimulate enhanced value-added products in order to conserve local and threatened livestock breeds. Several Traditional Pork Products (TPP) and Innovative Traditional Pork Products (ITPP) with health innovations from four untapped pig breeds in Spain (Porc Negre Mallorquí), Croatia (Turopolje), Italy (Cinta Senese) and Slovenia (Krškopolje) were analysed. Consumers' "Non-hypothetical" willingness to pay (WTP) and hedonic evaluation were investigated. An integrated experimental approach using two Non-Hypothetical Discrete Choice Experiment (NH-DCE) was carried out before and after a hedonic evaluation test. Results showed that the health innovative products (ITPP) received similar and even lower WTP than the "control" products (TPP) from the untapped pig breeds. The TPP outperformed products enriched with healthy ingredients or with reduced undesirable compounds. The potential demand for traditional and "unaltered" product from the rustic pig breeds could contribute to their conservation. A market niche exists, where consumers appreciate these high-quality products and where no "add-ons" are required to enhance their uptake.

Effects of naturally-produced lovastatin on carcass characteristics, muscle physico-chemical properties and lipid oxidation and cholesterol content in goats

This study investigated the carcass characteristics, physico-chemical properties, storage stability and cholesterol content of meat from goats fed with different levels of naturally-produced lovastatin used to mitigate enteric methane production. Twenty intact Saanen male goats of 5-6 months old with initial live weight of 25.8 ± 4.0 kg were randomly allotted into four dietary treatments containing 0 (Control), 2 (Low), 4 (Medium) and 6 mg (High) per kg live weight (LW) of naturally-produced lovastatin for 12 consecutive weeks. No differences were found in all the parameters measured except for full LW, hot and cold carcass weight, shear force, color and cholesterol content among the treatment groups. Aging had significant effects on all the parameters measured in this study except a* (redness) of meat. Meat samples in the Medium and High treatments were of higher lightness and yellowness, more tender and lower cholesterol levels. We conclude that, in addition to mitigate enteric methane emissions, dietary supplementation of naturally-produced lovastatin at 4 mg/kg LW could be a feasible feeding strategy to produce tender meat containing lower cholesterol.

Kimchi extracts as inhibitors of colour deterioration and lipid oxidation in raw ground pork meat during refrigerated storage

BACKGROUND

Kimchi is a Korean, traditional fermented food made from Korean cabbage, radish, fermented jeotgal, ginger, garlic, and red pepper powder. It is a good source of natural antioxidants such as phenolic compounds, flavonoids, vitamins, and carotenoids. In this study, the antioxidant effects of various kimchi extracts on raw ground pork during refrigerated storage were investigated. Raw ground pork samples were treated with ascorbic acid, butylated hydroxyl toluene, baechu kimchi extract (BKE), gat kimchi extract (GKE), puchu kimchi extract (PKE), and white kimchi extract (WKE) and compared with raw ground pork without antioxidant treatment (NC).

RESULTS

Increased metmyoglobin (MetMb), thiobarbituric acid reacting substance (TBARS), and total bacterial counts (TBC) were observed in all meat samples after storage, whereas pH, lightness, and redness values tended to decrease with increased storage time. All treated samples had lower TBARS and MetMb values and TBC compared to the control samples. Various kimchi ethanol extracts protected raw ground pork from lipid oxidation. The most potent antioxidant was GKE, whereas WKE was the weakest.

CONCLUSIONS

This study suggests that the tested extracts, especially kimchi, have potential as natural preservatives to reduce colour degradation, lipid oxidation, and bacterial count in raw ground pork meat. © 2018 Society of Chemical Industry.

Effect of clove (Syzygium aromaticum) and seaweed (Kappaphycus alvarezii) water extracts pretreatment on lipid oxidation in sun-dried sardines (Rastrineobola argentea) from Lake Victoria, Tanzania

Small indigenous fish species play a significant role in food and nutritional security of poor communities in developing countries. Sardines (Rastrineobola argentea) are fish species of Lake Victoria known to be a good source of health-promoting omega-3 fatty acids. Open sun drying is a common and traditional sardine processing and preservation method. Sun-dried products suffer from characteristic off-flavor due to lipid oxidation which discourage product consumption and limit diversification. This study investigated the use of clove (Syzygium aromaticum) and seaweed (Kappaphycus alvarezii) water extracts as natural antioxidants to impede lipid oxidation in sun-dried sardines. Lipid oxidation was assessed by peroxide value, volatile secondary oxidation products, and fatty acid profiles. The antioxidant capacity of extracts was evaluated by total phenolic content, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, and iron (Fe2+) chelating ability. Results showed that 5, 10, and 20 g/L clove extracts significantly reduced peroxidation in sun-dried sardines by 38.7%, 54.6%, and 56%, respectively. Clove extracts resulted in higher retention of omega-3 fatty acids and lower concentrations of secondary lipid oxidation products as opposed to seaweed counterpart. This research has demonstrated feasibility of pretreating whole, omega-3-rich small sardines with natural antioxidants to avert lipid oxidation during sun drying.