Chemical composition and antioxidant activity of commercial flours from Ceratonia siliqua and Prosopis spp

Insights into the phytochemical composition and antioxidant potential of the Tunisian Ceratonia siliqua L

Carob (Ceratonia siliqua L.) corresponds to an evergreen leguminous tree (Fabaceae family). The high phenolic content of numerous parts of carob has been deeply associated with several nutritional and functional benefits. The aim of this study was to investigate the physicochemical properties of ground carob pods and seeds, the effect of different extraction procedures as well a comprehensive phytochemical characterization of hydro-methanolic extracts (80/20 v/v) of pods and seeds by HPLC-DAD ESI-Q-TOF-MS/MS. Additionally, their antioxidant activity was evaluated using in vitro assays. The results showed thatthe dry matter (DM) values were 88.09% for pods and 89.10% for seeds, protein contents were 0.41 g/100 g DM for pods and 0.88 g/100 g DM for seedsand total sugars contents were 0.35 g/100 DM for pods and 26.70 g/100 g DM for seeds. Furthermore, the oil holding capacities (OHC) were 10.43 g/g for pods and 7.53 g/g for seeds, while the water holding capacities were 8.46 g/g for pods and 2.59 g/g for seeds.The hydro-methanolic extracts of both pods and seeds showed the presence of 53 secondary bioactive metabolites belonging to various classes(flavonoids, phenolic acids, tannins and non-phenolic compounds). The antioxidant activities were evidenced in DPPH (22.24 mg/ml for pods and 26.37 mg/ml for seeds), ABTS (198.50 mmol Eq Trolox/100 g for pods and 201.04 mmol Eq Trolox/100 g for seeds) and FRAP (0.39 mmol Eq Trolox/100 g for pods and 0.53 mmol Eq Trolox/100 g for seeds).Moreover,high significant (p ≤ 0.01) correlation coefficients were found between the antioxidant activity estimated by the DPPH method and total phenols (r = 0.943), orthodiphenols (r = 0.996), flavonoids (r = 0.880) and flavonols (r = 0.982). Nevertheless, lower correlations were detected with ABTS and FRAP methods.These results demonstrated that carob parts displayed an interesting potential that can be of interest for further valorizations as a natural antioxidant with multiple applications, namely functional food ingredients or prevention of many health problems.

Exploring Carob (Ceratonia siliqua L.): A Comprehensive Assessment of Its Characteristics, Ethnomedicinal Uses, Phytochemical Aspects, and Pharmacological Activities

The carob tree (Ceratonia siliqua L.) is currently considered one of the most valuable fruit and forest trees in various fields and sectors of activity. It is a versatile plant, belonging to the Fabaceae family. It is widely used in traditional medicine to treat many diseases such as diabetes, hypertension, and gastrointestinal disorders, given that all its parts (leaves, flowers, pods, seeds, wood, bark, and roots) are useful and hold value in many areas. Its importance has increased significantly in recent years. Originating from the Middle East, it is recognized for its ecological and industrial significance. Previous studies conducted on Ceratonia siliqua L. have revealed the presence of several compounds, including polyphenols, flavonoids, carbohydrates, minerals, and proteins. The carob tree demonstrates antihypertensive, antidepressant, anti-obesity, and antihyperglycemic activities. This plant is known for its medicinal and therapeutic virtues. Moreover, it is particularly interesting to consider the pharmacological activities of the major phytochemical compounds present in the different extracts of this plant, such as phenolic acids, for example, coumaric and gallic acids, as well as flavonoids such as kaempferol and quercetin. Therefore, this review aims to analyze some aspects of this plant, especially the taxonomy, cytogeography, traditional uses, phytochemical constituents, and pharmacological activities of Ceratonia siliqua L., in addition to its biological properties.

Optimization of Carob Products Preparation for Targeted LC-MS/MS Metabolomics Analysis

Carob (Ceratonia siliqua) is an exceptional source of significant bioactive compounds with great economic importance in the Mediterranean region, where it is widely cultivated. Carob fruit is used for the production of a variety of products and commodities such as powder, syrup, coffee, flour, cakes, and beverages. There is growing evidence of the beneficial effects of carob and the products made from it on a range of health problems. Therefore, metabolomics could be used to explore the nutrient-rich compounds of carob. Sample preparation is a crucial step in metabolomics-based analysis and has a great impact on the quality of the data obtained. Herein, sample preparation of carob syrup and powder was optimized, to enable highly efficient metabolomics-based HILIC-MS/MS analysis. Pooled powder and syrup samples were extracted under different conditions by adjusting pH, solvent type, and sample weight to solvent volume ratio (Wc/Vs). The metabolomics profiles obtained were evaluated using the established criteria of total area and number of maxima. It was observed that the Wc/Vs ratio of 1:2 resulted in the highest number of metabolites, regardless of solvent type or pH. Aqueous acetonitrile with a Wc/Vs ratio of 1:2 satisfied all established criteria for both carob syrup and powder samples. However, when the pH was adjusted, basic aqueous propanol 1:2 Wc/Vs and acidic aqueous acetonitrile 1:2 Wc/Vs provided the best results for syrup and powder, respectively. We strongly believe that the current study could support the standardization of the metabolomics sample preparation process to enable more efficient LC-MS/MS carob analysis.

Antioxidant and Antibacterial Activities of a Purified Polysaccharide Extracted from Ceratonia siliqua L. and Its Involvement in the Enhancement Performance of Whipped Cream

The main objective discussed in this research was to determine the structural characteristics of carob kibble water-soluble polysaccharide (KWSP), extracted from Ceratonia siliqua L., and to assess its in vitro antioxidant activities, as well as its effect on whipped cream. The results obtained through 13C, 1H, and the hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR) analysis indicated that KWSP had the characteristic bands of polysaccharides. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) suggested that KWSP is a hetero-polysaccharide composed of glucose and fructose, with an average molecular weight (Mw) amounting to 65 KDa. In addition, KWSP showed a good water holding capacity (WHC), a good oil holding capacity (OHC), and an emulsification stability, rated as 3.14 ± 0.05 g/g, 0.87 ± 0.02 g/g, and 71 ± 0.01%, respectively. The antioxidant activity of KWSP was investigated in vitro, demonstrating important DPPH and ABTS⋅+ radical scavenging activities and a good total antioxidant capacity. KWSP exhibited antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica. On the other hand, the incorporation of KWSP in whipped cream was investigated, to enhance its antioxidant capacity and consequently to extend its expiration date. Moreover, KWSP reduces the formation of conjugated dienes and trienes in cream fat.

Particle Size Effect of Integral Carob Flour on Bioaccessibility of Bioactive Compounds during Simulated Gastrointestinal Digestion

Carob fruit is native to the Mediterranean region and produced mainly in Portugal, Italy, Morocco and Turkey. The production of the carob fruit in Portugal is highly extensive and sustainable. Currently, carob flour (CF) production is mainly achieved after pulp separation, despite it having been demonstrated that the seeds improve the extraction efficiency of bioactive compounds such as polyphenols, promoting human health. This study aimed to produce an integral CF through an innovative process and assess its physicochemical and bioactive properties at different particle sizes throughout simulated gastrointestinal tract (GIT) digestion. The sugar content profile obtained throughout GIT digestion indicated that sucrose, the sugar present at the highest concentration in undigested CF, was digested and broken down into simple sugars, namely glucose and fructose. The total phenolic content (TPC) and antioxidant activity obtained for the ≤100 µm fraction were in accordance and gastric digestion promoted an increase in the TPC value compared to the undigested sample. The >100 µm fractions displayed a distinct profile from the ≤100 µm fraction. This study showed that the particle size affects the sugar, antioxidant and total phenolic content of CFs and also their gastrointestinal tract digestion. The ≤100 µm fraction demonstrated the most suitable profile as a functional food ingredient.

Nutritional ingredient by-product of the pistachio oil industry: physicochemical characterization

Pistachio flour obtained from oil industry was nutritionally characterized for use as food ingredient in functional foods. Proximal composition, jointly with mineral content, amino acids and fatty acid profile were studied. In addition, different components present in this food ingredient have been analyzed by attenuated total reflectance Fourier transform infrared spectroscopy and thermal properties of proteins were evaluated by differential scanning calorimetry. This flour presented high mineral content such as potassium, phosphorus, magnesium and calcium. Moreover, high amount of unsaturated fatty acids, mainly oleic and linoleic were found. Secondary structure of proteins mainly was formed by parallel β-sheet and α-helix. In the by-product, pistachio protein is in a native state and is able to be denatured at temperatures higher than 100 °C. Therefore, food processing of this ingredient can affect the structure of components.