Lychee (Litchi chinensis Sonn.) seed water extract as potential antioxidant and anti-obese natural additive in meat products

Differentiation of antioxidants in reducing oxidation and improving quality of ready-to-eat roasted shrimp after thermal sterilization

Sterilization is essential for ready-to-eat foods; however, it tends to degrade the quality of the product. To explore the role of antioxidants in regulating the edible quality of roasted Pacific white shrimp after sterilization, color changes, degree of oxidation, microstructure and quality of roasted shrimp treated with tea polyphenols, phytic acid, rosemary extract, and d-sodium erythorbate were investigated. Tea polyphenol-treated roasted shrimp had the lowest Maillard intermediate products and browning strength after sterilization; phytic acid significantly reduced carbonyl content and TBARS value; rosemary extract exhibited the lowest level of free radicals, while d-sodium erythorbate preserved a relatively intact myofibrillar structure. Correlation analysis revealed a negative correlation between the degree of oxidation and the edible quality of roasted shrimp after sterilization. Therefore, the addition of antioxidants inhibited oxidation and improved the quality of roasted shrimp, and different antioxidants had diverse effects on the quality improvement of roasted shrimp after thermal sterilization.

Non-edible fruit seeds: nutritional profile, clinical aspects, and enrichment in functional foods and feeds

Nowadays, fruits are gaining high demand due to their promising advantages on human health. Astonishingly, their by-products, that is, seeds and peels, account for 10-35% of fruit weight and are usually thrown as waste after consumption or processing. But it is neglected that fruit seeds also have functional properties and nutritional value, and thus could be utilized for dietary and therapeutic purposes, ultimately reducing the waste burden on the environment. Owing to these benefits, researchers have started to assess the nutritional value of different fruits seeds, in addition to the chemical composition in various bioactive constituents, like carotenoids (lycopene), flavonoids, proteins (bioactive peptides), vitamins, etc., that have substantial health benefits and can be used in formulating different types of food products with noteworthy functional and nutraceutical potential. The current review aims to comprehend the known information of nutritional and phytochemical profiling of non-edible fruits seeds, viz. apple, apricot, avocado, cherry, date, jamun, litchi, longan, mango, and papaya. Additionally, clinical studies conducted on these selected non-edible fruit seed extracts, their safety issues and their enrichment in food products as well as animal feed has also been discussed. This review aims to highlight the potential applications of the non-edible fruit seeds in developing new food products and also provide a viable alternative to reduce the waste disposal issue faced by agro-based industries.

Dietary Polyphenols as Prospective Natural-Compound Depression Treatment from the Perspective of Intestinal Microbiota Regulation

The broad beneficial effects of dietary polyphenols on human health have been confirmed. Current studies have shown that dietary polyphenols are important for maintaining the homeostasis of the intestinal microenvironment. Moreover, the corresponding metabolites of dietary polyphenols can effectively regulate intestinal micro-ecology and promote human health. Although the pathogenesis of depression has not been fully studied, it has been demonstrated that dysfunction of the microbiota-gut-brain axis may be its main pathological basis. This review discusses the interaction between dietary polyphenols and intestinal microbiota to allow us to better assess the potential preventive effects of dietary polyphenols on depression by modulating the host gut microbiota.

Effect of Rosemary Extract on Lipid Oxidation, Fatty Acid Composition, Antioxidant Capacity, and Volatile Compounds of Salted Duck Eggs

The purpose of our study was to determine the impact of rosemary extract in duck eggs, as determined by in vitro antioxidant capacity, lipid oxidation, fatty acid profiles, and flavor analyses. Three groups of salted duck eggs were compared: A control group and group enriched with 0.1% and 0.5% (w/v) rosemary extracts for 28 days of salting. In a time-dependent manner, the radical scavenging activity and reduction power of eggs with 0.5% (w/v) rosemary extract were significantly higher those of the control at 28 days after salting. The fatty acid profiles of salted egg were significantly affected by rosemary extract and salting time. Palmitic acid was the most abundant fatty acid in salted egg treated with rosemary extract, followed by linoleic acid and arachidonic acid. Furthermore, the treated eggs contained more docosahexaenoic acid than the control ones. And the treated eggs also have a considerable impact on the lipid oxidation process (primary and secondary oxidation). As a result, rosemary extract can be used as a natural antioxidant spice to prevent oxidation and extend the shelf life of eggs during storage. Furthermore, flavor research using solid phase microextraction - gas chromatography - mass spectrometry and an electronic nose demonstrated that adding rosemary extract to salted eggs could give them a distinct flavor.

Litchi chinensis seed prevents obesity and modulates the gut microbiota and mycobiota compositions in high-fat diet-induced obese zebrafish

Obesity continues to be a global public health challenge. Litchi chinensis seed is rich in bioactive ingredients with pharmacological effects, such as hypoglycemic activity and anti-oxidation. This study aimed to...

Self-assembled all-polysaccharide hydrogel film for versatile paper-based food packaging

Paper-based packaging generally has poor performances in the gas/oil barriers. This work reports a paper-based packaging material prepared via the modification of conventional papers with TEMPO-oxidized cellulose nanofibers (TOCN)/cationic guar gum (CGG) hydrogel film. Specifically, the hydrogel film modification was realized through a layer-by-layer deposition on paper. The hydrogel film modification significantly improved the mechanical and barrier properties of the paper. Specifically, the 4-layer hydrogel film modified paper showed a tensile strength of 34.03 MPa and a burst strength of 510 kPa, respectively. In contrast, the unmodified paper exhibited a tensile strength of 26.78 MPa and a bursting strength of 388 kPa. The packaging performance of this TOCN/CGG hydrogel film modified paper was demonstrated via the fresh mooncake packaging test. Such hydrogel film not only provided the oil resistance, but also maintained the mooncake's freshness. This material can serve as a green and sustainable food packaging.

Litchi (Litchi chinensis Sonn.): a comprehensive review of phytochemistry, medicinal properties, and product development

Since ancient times, litchi has been well recognized as a functional food for the management of various ailments. Many bioactives, including flavanoids, anthocyanins, phenolics, sesquiterpenes, triterpenes, and lignans, have been identified from litchi with a myriad of biological properties both in vitro and in vivo. In spite of the extensive research progress, systemic reviews regarding the bioactives of litchi are rather scarce. Therefore, it is crucial to comprehensively analyze the pharmacological activities and the structure-activity relationships of the abundant bioactives of litchi. Besides, more and more studies have focused on litchi preservation and development of its by-products, which is significant for enhancing the economic value of litchi. Based on the analysis of published articles and patents, this review aims to reveal the development trends of litchi in the healthcare field by providing a systematic summary of the pharmacological activities of its extracts, its phytochemical composition, and the nutritional and potential health benefits of litchi seed, pulp and pericarp with structure-activity relationship analysis. In addition, its by-products also exhibited promising development potential in the field of material science and environmental protection. Furthermore, this study also provides an overview of the strategies of the postharvest storage and processing of litchi.

Clean Label Alternatives in Meat Products

Food authorities have not yet provided a definition for the term "clean label". However, food producers and consumers frequently use this terminology for food products with few and recognisable ingredients. The meat industry faces important challenges in the development of clean-label meat products, as these contain an important number of functional additives. Nitrites are an essential additive that acts as an antimicrobial and antioxidant in several meat products, making it difficult to find a clean-label alternative with all functionalities. Another important additive not complying with the clean-label requirements are phosphates. Phosphates are essential for the correct development of texture and sensory properties in several meat products. In this review, we address the potential clean-label alternatives to the most common additives in meat products, including antimicrobials, antioxidants, texturisers and colours. Some novel technologies applied for the development of clean label meat products are also covered.

The effects of thermal treatment on the bacterial community and quality characteristics of meatballs during storage

Thermal treatment is a widely applied food processing technology in the meat industry due to its convenience. However, the interpretation of the changes in the bacterial community and quality properties in the thermal processed meat products have not been well established. Therefore, the effects of thermal treatment on the quality characteristics and bacterial communities in meatballs during storage at 4°C were investigated, which will provide a more comprehensive understanding of the influence of thermal treatment on the meat quality. Thermal treatment (121°C, 15 min) decreased the initial total viable bacterial counts by 2.1 log CFU/g and the diversity of the initial bacterial communities in meatballs. Compared with the thermal treatment group, a significantly more rapidly increasing trend of total volatile basic nitrogen and a decreasing trend of pH were observed in the control group. At the end of storage, the bacterial community was dominated by Streptococcus, Acinetobacter and Pseudomonas in the thermal treatment meatballs, whereas Pseudomonas, Pantoea, and Serratia. dominated the bacterial community of the control group. Besides, the predicted metabolic pathways revealed high levels of carbohydrate, amino acid, and lipid metabolism in the control group. This finding could contribute to a deep understanding of the influence of thermal treatment on the meat quality. Moreover, these results could provide a theoretical foundation for the development of alternative and novel nonthermal processing technologies for use in the meat industry.

Combination of liquid-phase pulsed discharge and ultrasonic for saponins extraction from lychee seeds

A skillfully combined method of liquid-phase pulsed discharge and ultrasonic (LPDU) had been developed for saponins extraction from lychee seeds. Single factor and response surface methods were used to optimize the system, respectively. The optimized conditions included 30% aqueous ethanol, 62.66 mL/g ratio of liquid to solid, 3 mm centre hole diameter of hollow electrode, 123 mL/min flow velocity, length of serpentine pipe of 15 cm, 276 W ultrasonic power, 47 °C ultrasonic temperature, and discharge voltage was fixed at 14 kV. Under these conditions, it obtained a maximum saponins yield of 51.30 ± 0.08 mg/g with 10 min, which was higher than those of LPD (42.33 ± 0.98 mg/g) with 24 min, ultrasonic assisted extraction (UAE) (41.80 ± 1.31 mg/g) with 30 min and maceration (38.72 ± 1.13 mg/g) with 180 min. Meanwhile, the energy consumption of LPDU was 7560 kJ/kg, which was notably lower than those of LPD (8820 kJ/kg), UAE (25875 kJ/kg) and maceration (10248 kJ/kg). We found that the saponin constituents of LPDU were similar to LPD, UAE, ME by HPLC content detection method, and found that LPDU had the highest degree of tissue damage after scanning electron microscope (SEM) comparison, which verified the reason for its high extraction efficiency. The results showed that LPDU was an effective technology for saponins extraction, which may be potentially applied in cosmetics, medicines and food chemistry.

Isolation and Purification of Polysaccharides from Litchi Seeds, with an Analysis of in Vitro Hypoglycemic Effect

Polysaccharides from litchi (Litchi chinensis) seeds were isolated and purified using ion exchange column chromatography. Molecular weight distribution of polysaccharides and monosaccharides were detected. Preliminary structural characterisation of polysaccharides was conducted using infrared, nuclear magnetic, and other spectroscopy techniques in combination with methylation analysis. In vitro cell culture experiments were designed to detect the effects of polysaccharides on cell growth and cellular glucose consumption. We extracted and analysed three polysaccharides from litchi seed. Monosaccharide composition and infrared spectroscopy detection showed that the skeleton structure of polysaccharides consisted of glucose and mannose. Polysaccharides 1 and 2 are similar and have relatively high glucose content (around 70%); polysaccharide 3 has 39.17% glucose only but is rich in arabinose (about 21.03%). In a certain range of use (50~1000 μg ml–1), polysaccharides 1 and 2 have no significant impacts on cell growth, while polysaccharide 3 can promote proliferation to some extent. All three polysaccharides can promote in vitro cellular glucose consumption, especially polysaccharide 3, which shows the strongest promotion, a significant dose effect, and synergistic effect with insulin. The above results highlight important roles of litchi seed polysaccharides in promoting cell growth and validate litchi seed polysaccharides as potential drugs for hypoglycaemia.

Lychee seed polyphenol inhibits Aβ-induced activation of NLRP3 inflammasome via the LRP1/AMPK mediated autophagy induction

Emerging evidence indicates that the enhancement of microglial autophagy inhibits the NLRP3 inflammasome mediated neuroinflammation in Alzheimer's disease (AD). Meanwhile, low density lipoprotein receptor-related protein 1 (LRP1) highly expressed in microglia is able to negatively regulate neuroinflammation and positively regulate autophagy. In addition, we have previously reported that an active lychee seed fraction enriching polyphenol (LSP) exhibits anti-neuroinflammation in Aβ-induced BV-2 cells. However, its molecular mechanism of action is still unclear. In this study, we aim to investigate whether LSP inhibits the NLRP3 inflammasome mediated neuroinflammation and clarify its molecular mechanism in Aβ-induced BV-2 cells and APP/PS1 mice. The results showed that LSP dose- and time-dependently activated autophagy by increasing the expression of Beclin 1 and LC3II in BV-2 cells, which was regulated by the upregulation of LRP1 and its mediated AMPK signaling pathway. In addition, both the Western blotting and fluorescence microscopic results demonstrated that LSP could significantly suppress the activation of NLRP3 inflammasome by inhibiting the expression of NLRP3, ASC, the cleavage of caspase-1, and the release of IL-1β in Aβ(1-42)-induced BV-2 cells. In addition, the siRNA LRP1 successfully abolished the effect of LSP on the activation of AMPK and its mediated autophagy, as well as the inhibition of NLRP3 inflammasome. Furthermore, LSP rescued PC-12 cells which were induced by the conditioned medium from Aβ(1-42)-treated BV-2 cells. Moreover, LSP improved the cognitive function and inhibited the NLRP3 inflammasome in APP/PS1 mice. Taken together, LSP inhibited the NLRP3 inflammasome-mediated neuroinflammation in the in vitro and in vivo models of AD, which was closely associated with the LRP1/AMPK-mediated autophagy. Thus, the findings from this study further provide evidences for LSP serving as a potential drug for the treatment of AD in the future.

Nutrient components, health benefits, and safety of litchi (Litchi chinensis Sonn.): A review

Litchi (Litchi chinensis Sonn.) is a tropical to subtropical fruit that is widely cultivated in more than 20 countries worldwide. It is normally consumed as fresh or processed and has become one of the most popular fruits because it has a delicious flavor, attractive color, and high nutritive value. Whole litchi fruits have been used not only as a food source but also for medicinal purposes. As a traditional Chinese medicine, litchi has been used for centuries to treat stomach ulcers, diabetes, cough, diarrhea, and dyspepsia, as well as to kill intestinal worms. Both in vitro and in vivo studies have indicated that whole litchi fruits exhibit antioxidant, hypoglycemic, hepatoprotective, hypolipidemic, and antiobesity activities and show anticancer, antiatherosclerotic, hypotensive, neuroprotective, and immunomodulatory activities. The health benefits of litchi have been attributed to its wide range of nutritional components, among which polysaccharides and polyphenols have been proven to possess various beneficial properties. The diversity and composition of litchi polysaccharides and polyphenols have vital influences on their biological activities. In addition, consuming fresh litchi and its products could lead to some adverse reactions for some people such as pruritus, urticaria, swelling of the lips, swelling of the throat, dyspnea, or diarrhea. These safety problems are probably caused by the soluble protein in litchi that could cause anaphylactic and inflammatory reactions. To achieve reasonable applications of litchi in the food, medical and cosmetics industries, this review focuses on recent findings related to the nutrient components, health benefits, and safety of litchi.

Effects and mechanisms of edible and medicinal plants on obesity: an updated review

In recent years, obesity has become a global public health issue. It is closely associated with the occurrence of several chronic diseases, such as diabetes and cardiovascular diseases. Some edible and medicinal plants show anti-obesity activity, such as fruits, vegetables, spices, legumes, edible flowers, mushrooms, and medicinal plants. Numerous studies have indicated that these plants are potential candidates for the prevention and management of obesity. The major anti-obesity mechanisms of plants include suppressing appetite, reducing the absorption of lipids and carbohydrates, inhibiting adipogenesis and lipogenesis, regulating lipid metabolism, increasing energy expenditure, regulating gut microbiota, and improving obesity-related inflammation. In this review, the anti-obesity activity of edible and medicinal plants was summarized based on epidemiological, experimental, and clinical studies, with related mechanisms discussed, which provided the basis for the research and development of slimming products. Further studies should focus on the exploration of safer plants with anti-obesity activity and the identification of specific anti-obesity mechanisms.

Polyphenols isolated from lychee seed inhibit Alzheimer's disease-associated Tau through improving insulin resistance via the IRS-1/PI3K/Akt/GSK-3β pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Lychee seed, the seed of Litchi chinensis Sonn. is one of the commonly used in traditional Chinese medicine (TCM). It possesses many pharmacological effects such as blood glucose and lipid-lowering effects, liver protection, and antioxidation. Our preliminary studies have proven that an active fraction derived from lychee seed (LSF) can significantly decrease the blood glucose level, inhibit amyloid-β (Aβ) fibril formation and Tau hyperphosphorylation, and improve the cognitive function and behavior of Alzheimer's disease (AD) model rats.

AIM OF THE STUDY

The aim of this study was to identify the main active components in LSF that can inhibit the hyperphosphorylation of Tau through improving insulin resistance (IR) in dexamethasone (DXM)-induced HepG2 and HT22 cells.

MATERIALS AND METHODS

The isolation was guided by the bioactivity evaluation of the improvement effect of IR in HepG2 and HT22 cells. The mRNA and protein expressions of IRS-1, PI3K, Akt, GSK-3β, and Tau were measured by RT-PCR, Western blotting, and immunofluorescence methods, respectively.

RESULTS

After extraction, isolation, and elucidation using chromatography and spectrum technologies, three polyphenols including catechin, procyanidin A1 and procyanidin A2 were identified from fractions 3, 5, and 9 derived from LSF. These polyphenols inhibit hyperphosphorylated Tau via the up-regulation of IRS-1/PI3K/Akt and down-regulation of GSK-3β. Molecular docking result further demonstrate that these polyphenols exhibit good binding property with insulin receptor.

CONCLUSIONS

catechin, procyanidin A1, and procyanidin A2 are the main components in LSF that inhibit Tau hyperphosphorylation through improving IR via the IRS-1/PI3K/Akt/GSK-3β pathway. Therefore, the findings in the current study provide novel insight into the anti-AD mechanism of the components in LSF derived from lychee seed, which is valuable for the further development of a novel drug or nutrient supplement for the prevention and treatment of AD.

Systematic evaluation of the physicochemical properties and the volatile flavors of yak meat during chilled and controlled freezing-point storage

In this study, the physicochemical properties (total volatile basic nitrogen (TVB-N), pH, and peroxide value) and the volatile flavors of yak meat were systematically evaluated during chilled (0 °C) and controlled freezing-point (- 2 °C) storage. The TVB-N reached 15.21 mg/100 g after 18 days of storage at 0 °C, which exceeded the secondary freshness value according to the Chinese national standard. For storage at - 2 °C, the TVB-N did not exceed 15 mg/100 g until 24 days. Compared with storage at 0 °C, the samples stored at - 2 °C had a slower rate of increase in TVB-N, pH, and peroxide values. The changes in volatile compounds in yak meat during storage at - 2 °C and 0 °C for 24 days were investigated using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). The correlations between the changes in the volatile compound contents and meat quality deterioration revealed significant negative correlations (r _min = 0.902, p < 0.05) between some aldehyde flavor components (nonanal, heptanal, benzaldehyde, decanal, and myristal) and TVB-N in the samples stored at controlled freezing-point and chilled temperatures. The decreases in nonanal, benzaldehyde, and myristal contents in yak meat followed zero order reaction kinetics. This result indicated, because of the highly selective and sensitive colorimetric detection method, that volatile compounds can effectively predict the decay in quality of yak meat stored at low temperature in advance. Thus, based on physicochemical and volatile flavor analyses, a new method is proposed to investigate the storage and preservation of yak meat.

Effect of Chitosan–Tomato Plant Extract Edible Coating on the Quality, Shelf Life, and Antioxidant Capacity of Pork during Refrigerated Storage

The aim of this study was to evaluate the effectiveness of chitosan–tomato plant extract (C-TPE) edible coating (EC) on the physicochemical, microbiological, sensory, and antioxidant capacity changes of pork during storage. Edible coatings prepared with chitosan 1%, acetic acid 1%, glycerol, and TPE (0.1% and 0.3%) were tested. Slices of pork were submerged in different treatments (T1: C 1%; T2: C 1% + TPE 0.1%; T3: C 1% + TPE 0.3%; T4: control) and stored at 4 °C. The different treatments showed the best results in physicochemical and microbiological analyses, with reduced microbial population relative to the control. The highest antioxidant capacity and total phenolic content were shown in T3, and the overall acceptance was better in T2. The results show that the application of C with the addition of natural extracts, such as the tomato plant with antioxidant and antimicrobial properties, can be an alternative method for preserving pork.

Antioxidant effect of oregano essential oil during various storage meat time of hybrid combination Ross 308

This study was conducted to evaluate the effect of Origanum vulgare L. Hirtum essential oil on the oxidation stability of raw chicken meat. Oregano essential oil was applied in a different way, on the one hand in a feed for broiler chickens (E1) and on the other hand on a surface of chicken thighs (E2). Broiler chickens were fed during the experimental period in the all groups with commercial feed mixtures except the experimental group of E1 (with the addition of 0.05% oregano essential oil, 50 g EO per 100 g of the feed mixture). In E2 was application of oregano essential oil (0.5%) on surface of thighs 1 mL per 60 g of meat realized. The oxidative stability of the chicken meat was investigated in the same way, 8th days after vacuum-packed and stored at temperature 4 °C and 6, 9 and 12 months after vacuum-packed and storage at -18 °C. The samples of the E1 consisted of breast and thigh muscles with skin (150 g) and of the E2 thigh muscle with skin (60 g). The impact of oregano essential oil was measured by content of fat and peroxide value (PV). Fat content in both experiments was not affected by storage time and EO addition. Content of chicken meat fat in E1 in control group ranged between M = 9.64 – 12.95 g.100 g-1 and in experimental group contained similar amount of fat mean from M = 9.94 – 12.24 g.100 g-1; E2: in control group M = 7.01 – 7.73 g.100 g-1 and in experimental group M = 6.15 – 8.03 g.100 g-1. Measured peroxide values confirm that oregano essential oil has effect on broiler chicken meat oxidative stability, if applied to feed, manifested statistically significant differences between control and experimental group. The mean of peroxide value in control group of E1 was M = 0.58 –3.60 µmol O2.kg-1 and in experimental group was M = 1.06 – 2.11 µmol O2.kg-1. We found not statistically significant difference in peroxide values, if applied oregano essential oil to raw chicken meat. The results impact of oregano essential oil on chicken meat comparable to control group, but a tendency to improve oxidative stability was indicated.

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.

Astratides: Insulin-Modulating, Insecticidal, and Antifungal Cysteine-Rich Peptides from Astragalus membranaceus

Astragalus membranaceus root, Huang Qi in Chinese, is a popular medicinal herb traditionally used to regulate blood glucose. Herein, the identification and characterization of two families of cysteine-rich peptides (CRPs), designated α- and β-astratides, from A. membranaceus roots are reported. Proteomic analysis showed that α-astratide aM1 and β-astratide bM1 belong to two distinct CRP families. The six-cysteine-containing and proline-rich α-astratide aM1 displayed high sequence identity to Pea Albumin 1 Subunit b (PA1b), while the eight-cysteine-containing β-astratide bM1 showed sequence similarity to plant defensins. An antifungal assay revealed that bM1 possessed potent antifungal activity. In contrast, aM1 showed a cytotoxic effect against insect Sf9 cells. More importantly, aM1 decreased insulin secretion in mouse pancreatic β cells, suggesting it could interfere in glucose homeostasis, which accounts for the adaptogenic property of A. membranaceus. Phylogenetic clustering analysis suggested that the proline-rich aM1 is a putative prolyl oligopeptidase inhibitor and belongs to a novel subfamily of PA1b-like peptides, while bM1 belongs to a new subfamily of plant defensins. Together, the study reveals that astratides are multifunctional CRPs in plants, which expand the existing library of PA1b-like peptides and plant defensins and further our understanding of their roles in host-defense system and leads as peptidyl therapeutics.

Natural antioxidants used in meat products: A brief review

The lipoperoxidation and the oxidation of pigments and proteins reduces the quality and nutritional value of meat products. The use of antioxidants slows down this reaction, preserving the characteristics of the product during its storage and prolonging its useful life. The use of synthetic antioxidants in food products has been the subject of several toxicological studies. Currently, the call for antioxidants from natural sources stands out. Investigations in this sense should be conducted considering the complex mechanism of reactive oxygen species (ROS) and interactions with cellular constituents to elucidate the mechanism of action of synthetic antioxidants and natural sources. Although natural additives appear as an alternative to meet the various market niches and associate natural antioxidants to active packaging as they are progressively released into the product. In this review, we present research with natural antioxidants that could be used satisfactorily in meat products, in addition to recent studies that use them in active packaging.

Polyphenols Derived from Lychee Seed Suppress Aβ (1-42)-Induced Neuroinflammation

Amyloid-β (Aβ) is commonly recognized as the most important factor that results in neuronal cell death and accelerates the progression of Alzheimer’s disease (AD). Increasing evidence suggests that microglia activated by Aβ release an amount of neurotoxic inflammatory cytokines that contribute to neuron death and aggravate AD pathology. In our previous studies, we found that lychee seed fraction (LSF), an active fraction derived from the lychee seed, could significantly improve the cognitive function of AD rats and inhibit Aβ-induced neuroinflammation in vitro, and decrease neuronal injuries in vivo and in vitro. In the current study, we aimed to isolate and identify the specific components in LSF that were responsible for the anti-neuroinflammation effect using preparative high performance liquid chromatography (pre-HPLC), liquid chromatography-mass spectrometry (LC-MS), and nuclear magnetic resonance (NMR) methods. To this end, we confirmed two polyphenols including catechin and procyanidin A2 that could improve the morphological status of BV-2 cells and suppress the release, mRNA levels, and protein expression of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) through downregulating the nuclear factor-κB (NF-κB) signaling pathway using ELISA, RT-PCR, and Western blotting methods. Furthermore, catechin and procyanidin A2 could inhibit Aβ-induced apoptosis in BV-2 cells by upregulating Bcl-2 and downregulating Bax protein expression. Therefore, the current study illustrated the active substances in lychee seed, and first reported that catechin and procyanidin A2 could suppress neuroinflammation in Aβ-induced BV-2 cells, which provides detailed insights into the molecular mechanism of catechin and procyanidin A2 in the neuroprotective effect, and their further validations of anti-neuroinflammation in vivo is also essential in future research.

Practical use of natural antioxidants in meat products in the U.S.: A review

Historically, meat and poultry processors in the U.S. have relied on the use of synthetic antioxidants like butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, and propyl gallate, as well as tocopherols to prevent lipid and protein oxidation. There is a trend towards utilizing natural antioxidants as replacements for synthetic ones. Some processors are already using multi-functional ingredients, such as rosemary and oregano, approved for use as spices and natural flavors to curb oxidation. Yet, there are still other ingredients that have not been applied in this fashion. Spices and natural flavors can often be incorporated in products that have defined statements of identity or composition. Further, these ingredients allow the processor to transition to a clean label without compromising the shelf life and quality of the products. Spices and natural flavors may have higher minimum effective concentrations than their synthetic counterparts, but they will offer increased consumer acceptability, decreased potential health risks, and can often achieve the same degree of oxidation prevention.

Lychee Seed Fraction Inhibits Aβ(1-42)-Induced Neuroinflammation in BV-2 Cells via NF-κB Signaling Pathway

In our previous studies, an active fraction derived from lychee seed could inhibit β-amyloid-induced apoptosis of PC12 cells and neurons. The primarily microglia cells are recognized as the brain’s resident macrophages and thought to remodel of the brain by removing presumably redundant, apoptotic neurons. In the current study, we aimed to investigate the anti-neuroinflammation effect of lychee seed fraction (LSF) in Aβ(1-42)-induced BV-2 cells and the underlying mechanism. The morphology results displayed that LSF could improve the status of Aβ(1-42)-induced BV-2 cells. The enzyme-linked immunosorbent assay, real-time PCR, and Western blotting results showed that LSF could significantly reduce the release, mRNA levels, and protein expressions of the pro-inflammatory cytokines such as interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in Aβ(1-42)-induced BV-2 cells, which were downregulated through suppressing the NF-κB signaling pathway. Furthermore, LSF could upregulate Bcl-2 and downregulate Bax, Caspase-3, and cleaved-PARP protein expressions. Taken together, our results first demonstrated that LSF could suppress the inflammatory response via inhibiting NF-κB signaling pathway, and inhibit apoptosis in Aβ(1-42)-induced BV-2 cells. Our findings further prove that LSF as a potential drug may be used for treating AD in the future.

Systemic Perturbations of Key Metabolites in Type 2 Diabetic Rats Treated by Polyphenol Extracts from Litchi chinensis Seeds

Our previous research obtained Litchi chinensis Sonn. seeds extract (LSE) which showed hypoglycaemic effects on type 2 diabetes (T2D) rats. In order to understand the detailed pathogenesis of diabetes intervened by LSE, the metabonomics strategy was used. As a result, LSE decreased the insulin resistance index and the levels of glucose in urine through elevating the mRNA level of insulin, while decreasing the expression of glucagon to enhance the function of the pancreas. Meanwhile, LSE regulated the glucose and fatty acid metabolisms via increasing the expression of glucose transporter (Glu) 2, Glu4, insulin receptor (IR), and IR substrate-2 (IRS2). LSE effectively restored the impairment of the IRS2/PI3K/Akt/mTOR insulin signaling in the livers. All in all, LSE played a pivotal role in the treatment of T2D through regulation of broad-spectrum metabolic changes and inhibition of the glycogenesis, proteolysis, and lipogenesis in T2D rats.

Extraction, chemical characterization and antioxidant activity of Litchi chinensis Sonn. and Avena sativa L. seeds extracts obtained from pressurized n-butane

The extraction of litchi (Litchi chinensis Sonn.) and oat (Avena sativa L.) seeds were investigated using n-butane as pressurized solvent by evaluating the effect of pressure in the range of 7-100 bar and temperature from 25 to 70 °C on the extract yield and chemical composition together with the antioxidant activity of the extracts obtained. It was experimentally observed extraction yields for both seeds up to ~3.5 wt%, with a total phenolic content around 126.4 mg GAE/100 g of extract, and an antioxidant activity up to 78.36%. Oat seeds extract presented higher values of these parameters evaluated compared to litchi extract. Based on the results found, it seems that n-butane may be a promising solvent to conventional extraction methods, as mild operating conditions and eco-friendly solvent can be used to provide good results without any residues in the final product.

Antioxidant Enzyme Activities and Lipid Oxidation in Rape (Brassica campestris L.) Bee Pollen Added to Salami during Processing

The present research investigated the antioxidant effect of rape (Brassica campestris L.) bee pollen (RBP) on salami during processing. Eight flavonoids in RBP ethanol extract were quantified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis, and quercetin, rutin, and kaempferol were the major bioactive compounds. The RBP ethanol extract exhibited higher total antioxidant capacity than 6-hydroxy-2,5,7,8-tertramethylchromancarboxylic acid (trolox) at the same concentration. The salami with 0.05% RBP extract had higher catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities than that of the control throughout the processing time (p < 0.05). Significant decreases in peroxide value (POV) and thiobarbituric acid-reactive substances (TBARS) were obtained in the final salami product with 0.05% RBP ethanol extract or 1% RBP (p < 0.05). These results suggested that RBP could improve oxidative stability and had a good potential as a natural antioxidant for retarding lipid oxidation.

ω-3 in meat products: benefits and effects on lipid oxidative stability

Although ω-3 intake has been associated with numerous health benefits, its addition to certain food matrices, and in particular meat products, may involve various technological barriers influencing the final quality of the products. Lipid oxidation must be highlighted due to the modification of both the sensory characteristics and the shelf-life of meat products. In order to reduce the impact of chemical changes and promote oxidative stability, the use of natural antioxidants has gained ground owing to the health and safety advantages linked to its effectiveness at reducing lipid oxidation. Many natural compounds have also been successfully tested in animal feed, in order to protect the raw meat materials and reduce the risk of lipid oxidation in processed products. This review aims to address the challenges and advantages of the incorporation of ω-3 fatty acids in raw meat materials and processed meat products, and to describe the use of different compounds to enhance lipid oxidative stability. © 2015 Society of Chemical Industry.

Antioxidant Efficacy of Litchi (Litchi chinensis Sonn.) Pericarp Extract in Sheep Meat Nuggets

In the present study, the efficacy of litchi fruit pericarp (LFP) extract (0.5%, 1.0% and 1.5% concentration) in retarding lipid oxidation of cooked sheep meat nuggets was evaluated and compared to butylated hydroxyl toluene (BHT, 100 ppm). The total phenolic content and antioxidant potential of LFP extracts were determined. The thiobarbituric acid reactive substance (TBARS) values were evaluated to assess the potential of LFP extracts as natural antioxidants for oxidative stability of cooked nuggets during 12 days of refrigerated storage. Results show that total phenolics content in 10 mg LFP powder was comparable to 100 ppm BHT, but 15 mg LFP powder had significantly higher (p < 0.05) total phenolics content and reducing power than the synthetic antioxidant. LFP extract did not affect pH, cooking yield and the sensory attributes of cooked nuggets. Non-treated control and nuggets with 1.0% LFP extract had significantly lower total phenolics than nuggets with 1.5% extract and BHT. TBARS values were significantly lower (p < 0.05) throughout the storage period in cooked meat nuggets containing either LFP extract or BHT than in non-treated control. Results indicate that LFP extracts are promising sources of natural antioxidants and can potentially be used as functional food additives in meat products at 1.5% without affecting products’ acceptability.

Litchi chinensis: medicinal uses, phytochemistry, and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Litchi chinensis Sonn. (Sapindaceae) has been widely used in many cultures for the treatment of cough, flatulence, stomach ulcers, diabetes, obesity, testicular swelling, hernia-like conditions, and epigastric and neuralgic pains. The ethnopharmacologial history of L. chinensis indicated that it possesses hypoglycemic, anticancer, antibacterial, anti-hyperlipidemic, anti-platelet, anti-tussive, analgesic, antipyretic, hemostatic, diuretic, and antiviral activities.

AIM OF THE REVIEW

The aim of this review is to provide up-to-date information on the botanical characterization, distribution, traditional uses, and chemical constituents, as well as the pharmacological activities and toxicity of L. chinensis. Moreover, the focus of this review is the possible exploitation of this plant to treat different diseases and to suggest future investigations.

MATERIALS AND METHODS

To provide an overview of the ethnopharmacology, chemical constituents, and pharmacological activities of litchi, and to reveal their therapeutic potentials and being an evidence base for further research works, information on litchi was gathered from scientific journals, books, and worldwide accepted scientific databases via a library and electronic search (PubMed, Elsevier, Google Scholar, Springer, Scopus, Web of Science, Wiley online library, and pubs.acs.org/journal/jacsat). All abstracts and full-text articles were examined. The most relevant articles were selected for screening and inclusion in this review.

RESULTS

A comprehensive analysis of the literature obtained through the above-mentioned sources confirmed that ethno-medical uses of L. chinensis have been recorded in China, India, Vietnam, Indonesia, and Philippines. Phytochemical investigation revealed that the major chemical constituents of litchi are flavonoids, sterols, triterpenens, phenolics, and other bioactive compounds. Crude extracts and pure compounds isolated from L. chinensis exhibited significant antioxidant, anti-cancer, anti-inflammatory, anti-microbial, anti-viral, anti-diabetic, anti-obesity, hepato-protective, and immunomodulatory activities. From the toxicological perspective, litchi fruit juice and extracts have been proven to be safe at a dose 1 g/kg.

CONCLUSIONS

Phytochemical investigations indicated that phenolics were the major bioactive components of L. chinensis with potential pharmacological activities. The ethnopharmacological relevance of L. chinensis is fully justified by the most recent findings indicating it is a useful medicinal and nutritional agent for treating a wide range of human disorders and aliments. Further investigations are needed to fully understand the mode of action of the active constituents and to fully exploit its preventive and therapeutic potentials.