Tannin in Ruminant Nutrition: Review

Tannins are polyphenols characterized by different molecular weights that plants are able to synthetize during their secondary metabolism. Macromolecules (proteins, structural carbohydrates and starch) can link tannins and their digestion can decrease. Tannins can be classified into two groups: hydrolysable tannins and condensed tannins. Tannins are polyphenols, which can directly or indirectly affect intake and digestion. Their ability to bind molecules and form complexes depends on the structure of polyphenols and on the macromolecule involved. Tannins have long been known to be an "anti-nutritional agent" in monogastric and poultry animals. Using good tannins' proper application protocols helped the researchers observe positive effects on the intestinal microbial ecosystem, gut health, and animal production. Plant tannins are used as an alternative to in-feed antibiotics, and many factors have been described by researchers which contribute to the variability in their efficiencies. The objective of this study was to review the literature about tannins, their effects and use in ruminant nutrition.

The effects of Cynara scolymus L. supplementation on liver enzymes: A systematic review and meta-analysis

OBJECTIVE

A systematic review and meta-analysis was conducted to summarise studies conducted on the effects of artichoke supplementation on liver enzymes.

METHODS

Suitable studies were detected by searching online databases, including Medline, Embase, Cochrane Library, and Scopus databases, until 05 June 2021. As liver enzymes were reported in different units, standardised mean differences (SMD) were used and data were pooled using a random-effects model. Heterogeneity, publication bias, and sensitivity analysis were also assessed.

RESULTS

Pooled analysis, of eight clinical trials, revealed that artichoke supplementation significantly reduced the concentration of aspartate aminotransferase (AST) (P = .001) and alanine transaminase (ALT) (P = .016), in comparison with placebo. Subgroup analysis suggested that artichoke administration significantly reduces AST and ALT in patients with non-alcoholic fatty liver disease (P = .003 for AST and P < .001 for ALT), and ALT among overweight/obese subjects (P = .025).

CONCLUSIONS

Artichoke supplementation elicited significant reductions in liver enzymes, especially among patients with non-alcoholic fatty liver disease.

Artichoke by Products as a Source of Antioxidant and Fiber: How It Can Be Affected by Drying Temperature

The reuse of food industry by-products constitutes one of the essential pillars of the change from a linear to a circular economic model. Drying is one of the most affordable techniques with which to stabilize by-products, making their subsequent processing possible. However, it can affect material properties. The objective of this study was to assess the effect of the drying temperature on the drying kinetics and final quality of the main artichoke processing by-products, bracts and stems, which have never been studied as independent materials. For this purpose, air drying experiments at different temperatures (40, 60, 80, 100 and 120 °C) were carried out. The alcohol insoluble residue (AIR) and the total phenolic content (TPC), antioxidant capacity (AC) and vitamin C (VC) of the fresh and dried samples were determined. The bracts dried faster than the stems, increasing drying rate with temperature. The two by-products presented relatively large amounts of AIR, the content being higher in bracts, but better functional properties in stems. The TPC, AC and VC values of the dried samples decreased in relation to the fresh samples, with the temperatures of 40 °C (bracts) and 120 °C (stems) being the most adequate for the purposes of preserving these characteristics.

Chemical Composition, Antioxidant Potential and Enzymes Inhibitory Properties of Globe Artichoke By-Products

In this study, chemical composition and in vitro biological activities of artichoke by-products (leaves, floral stems and bracts) issued from two Tunisian varieties were evaluated. Analysis was performed by means of high-performance liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometric (LC/DAD/ESI-MS). Total phenolic (TPC) and flavonoid (TFC) contents as well as the antioxidant activity conducted by three complementary methods, DPPH, ABTS and FRAP tests, were performed for each sample. Enzyme inhibitory effects against acetylcholinesterase, butyrylcholinesterase and α-amylase were also studied. Results showed that TPC and TFC varied according to variety as well as the plant part. Bracts presented the highest TPC values (10-15 mg GAE/g DW), while leaves were distinguished by the highest TFC values (52-58 mg EQ/g DW). In vitro assays showed that Violet d'Hyères bracts and Blanc d'Oran leaves present the most antioxidant activities (30.040 and 20.428 mgET/gDW, respectively, by the DPPH method). Leaves demonstrated the highest acetylcholinesterase and butyrylcholinesterase inhibitory effects. Moreover, all organs displayed a noticeable inhibition towards α-amylase. LC/DAD/MS analysis revealed that artichoke by-products are a potential source of biopharmaceuticals such as luteolin derivatives from leaves and mono/dicaffeoylquinic acids in the other parts. This research demonstrates that globe artichoke by-products, unexploited in our country, are a promising source of natural health promoting compounds with potential applications in the food and pharmaceutical industries.

A New Insight on Cardoon: Exploring New Uses besides Cheese Making with a View to Zero Waste

Cardoon, Cynara cardunculus L., is a perennial plant whose flowers are used as vegetal rennet in cheese making. Cardoon is native from the Mediterranean area and is commonly used in the preparation of salads and soup dishes. Nowadays, cardoon is also being exploited for the production of energy, generating large amount of wastes, mainly leaves. These wastes are rich in bioactive compounds with important health benefits. The aim of this review is to highlight the main properties of cardoon leaves according to the current research and to explore its potential uses in different sectors, namely the food industry. Cardoon leaves are recognized to have potential health benefits. In fact, some studies indicated that cardoon leaves could have diuretic, hepato-protective, choleretic, hypocholesterolemic, anti-carcinogenic, and antibacterial properties. Most of these properties are due to excellent polyphenol profiles, with interesting antioxidant and antimicrobial activities. These findings indicate that cardoon leaves can have new potential uses in different sectors, such as cosmetics and the food industry; in particular, they can be used for the preparation of extracts to incorporate into active food packaging. In the future, these new uses of cardoon leaves will allow for zero waste of this crop.

Grown to be Blue-Antioxidant Properties and Health Effects of Colored Vegetables. Part II: Leafy, Fruit, and Other Vegetables

The current trend for substituting synthetic compounds with natural ones in the design and production of functional and healthy foods has increased the research interest about natural colorants. Although coloring agents from plant origin are already used in the food and beverage industry, the market and consumer demands for novel and diverse food products are increasing and new plant sources are explored. Fresh vegetables are considered a good source of such compounds, especially when considering the great color diversity that exists among the various species or even the cultivars within the same species. In the present review we aim to present the most common species of colored vegetables, focusing on leafy and fruit vegetables, as well as on vegetables where other plant parts are commercially used, with special attention to blue color. The compounds that are responsible for the uncommon colors will be also presented and their beneficial health effects and antioxidant properties will be unraveled.

Agro-Food Byproducts as a New Source of Natural Food Additives

Nowadays, the agro-food industry generates high amounts of byproducts that may possess added value compounds with high functionality and/or bioactivity. Additionally, consumers' demand for healthier foodstuffs has increased over the last years, and thus the food industry has strived to answer this challenge. Byproducts are generally secondary products derived from primary agro-food production processes and represent an interesting and cheaper source of potentially functional ingredients, such as peptides, carotenoids, and phenolic compounds, thus promoting a circular economy concept. The existing body of work has shown that byproducts and their extracts may be successfully incorporated into foodstuffs, for instance, phenolic compounds from eggplant can be potentially used as a mulfitunctional food additive with antimicrobial, antioxidant, and food colorant properties. As such, the aim of this review is to provide insights into byproducts and their potential as new sources of foodstuffs additives.