Effect of carob variety and roasting on the antioxidant capacity, and the phenolic and furanic contents of carob liquors

Chemical Composition, Physical Properties, and Aroma Profile of Ethanol Macerates of Mistletoe (Viscum album)

Maceration parameters such as alcohol and mistletoe content were studied to obtain high-quality macerates to produce biska, a traditional Istrian herbal spirit. An ethanol–water solution containing 25, 40, 55, and 70 v/v% ethanol and 20, 40, and 80 g/L mistletoe was macerated and pH, total acids, extract content, and color parameters were measured. Volatile compounds were determined by GC/MS. More than 150 different volatile compounds were detected. The composition of the ethanol–water solution and mistletoe content affects the values of total extract, total acids, and color. Samples with lower alcohol content have a higher number of different acids, aldehydes, alcohols, esters, and ketones, while macerates with higher alcohol content are rich in hydrocarbons and terpenes. Ethyl decanoate; ethyl hexynoate; ethyl octanoate; benzaldehyde; hexanal; octanal; and the terpene compounds limonene, cymene, menthone, humulene, eucalyptol, linalol, and borneol contribute significantly to the aroma of the macerates due to a low odor threshold. Ylangene and α- and β-bourbonene are tentatively determined new terpene molecules that are not found in the mistletoe literature, as well as thujone, which was also detected. For the preparation of aromatic macerates, 40–50 v/v% ethanol and about 40 g/L mistletoe should be used.

Linking the Dynamic Changes in the In Vitro Antioxidant Activity of Carob Kibbles upon Roasting to the Chemical and Structural Changes Revealed by FTIR Spectroscopy

Recent studies have highlighted the potential of utilizing carob kibbles as a bioactive-rich food ingredient associated with substantial health benefits. Roasting is a key process in enhancing the sensory characteristics of carob kibbles, also affecting the bioactive polyphenols and leading to the formation of Maillard reaction products (MRPs), including the polymeric melanoidins that are associated with a high antioxidant potential but remain unexplored in carob. In this work, we employed for the first time attenuated total reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy to probe the dynamic chemical and structural changes upon the roasting of carob kibbles, along with the investigation of the in vitro antioxidant activity through the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the determination of the total polyphenolic, proanthocyanidin, gallic acid and cinnamic acid contents. Roasting significantly enhanced the in vitro antioxidant activity of the polyphenolic carob extracts, with different rates at distinct roasting temperatures. The ATR-FTIR analysis enabled the identification of the changes in the structural features of polyphenolic compounds that were related to the improved antioxidant activity upon roasting. Furthermore, the detection of characteristic signatures for the polymeric melanoidins in the infrared (IR) fingerprint region provided the first evidence for the formation and structural properties of these complex, diverse compounds in roasted carob kibbles.

Carob Pulp: A Nutritional and Functional By-Product Worldwide Spread in the Formulation of Different Food Products and Beverages. A Review

Carob (Ceratonia siliqua L.) pod is a characteristic fruit from the Mediterranean regions. It is composed by seeds, the valuable part due to the extraction of locust bean gum, and the pulp, considered a by-product of the fruit processing industry. Carob pulp is a mixture of macro- and micronutrients, such as carbohydrates, vitamins and minerals, and secondary metabolites with functional properties. In the last few years, numerous studies on the chemical and biological characteristics of the pulp have been performed to encourage its commercial use. Its potential applications as a nutraceutical ingredient in many recipes for food and beverage elaborations have been extensively evaluated. Another aspect highlighted in this work is the use of alternative processes or conditions to mitigate furanic production, recognized for its toxicity. Furthermore, carob pulp’s similar sensorial, chemical and biological properties to cocoa, the absence of the stimulating alkaloids theobromine and caffeine, as well as its low-fat content, make it a healthier potential substitute for cocoa. This paper reviews the nutritional and functional values of carob pulp-based products in order to provide information on the proclaimed health-promoting properties of this interesting by-product.

Physicochemical and aromatic characterization of carob macerates produced by different maceration conditions

Carob liqueur is an alcoholic drink (minimum 15% v/v of ethanol and 100 g/L of sugar) typical for the Mediterranean countries. In the current work, carob macerate produced by maceration of carob pods in hydroalcoholic base at different maceration conditions was characterized for the first time based on its aroma compounds/profile, physicochemical parameters, and chromatic characteristics. The results confirm the migration process of bioactive compounds, aroma compounds, and sugars flowing from the carob pod to the hydroalcoholic base. Changes in ethanol concentration modify the physical properties of the solvent and influence the phenolic and aroma compounds extraction, color, and acidity of the obtained samples. The higher content of phenolic compounds was determinate in the samples obtained in the darkness. The amounts of phenols were in the range of some red fruit liqueurs or walnut liqueurs, and sugars (mostly sucrose) ranging between 96 and 107 g/L. Twenty-six (out of total 94) aroma compounds were detected in all samples, of which 17 esters, 3 alcohols, 4 ketones, and 2 acids. Low molecular weight ethyl esters, ethyl hexanoate, ethyl 2-methyl propanoate, ethyl octanoate, ethyl benzoate, ethyl butanoate, and ethyl cinnamate, were the most abundant. Carob pod maceration in 50% v/v hydroalcoholic base (1:5 solid to liquid ratio) in darkness at room temperature during 8 weeks can be recommended as optimal maceration conditions for production of the aromatic carob macerate with functional properties.

The Influence of In Vitro Gastrointestinal Digestion on the Chemical Composition and Antioxidant and Enzyme Inhibitory Capacities of Carob Liqueurs Obtained with Different Elaboration Techniques

Carob liqueur is a traditional Mediterranean alcoholic beverage obtained via a wide range of production techniques contributing to the different organoleptic attributes of the final product. The aim of this research was to evaluate the stability of the chemical composition and biological capacities (antioxidant and enzyme inhibition) under in vitro simulated gastrointestinal digestion of liqueurs prepared by flavouring the fig spirit with carob pulp by maceration, distillation, percolation, or aqueous and hydro-alcoholic infusions. For this purpose, the phenolic and furanic compositions, the total phenolic (TPC) and flavonoid (TFC) contents, antioxidant capacity (AC), and enzyme inhibitory potential against acethylcholinesterase, tyrosinase, α-glucosidase and α-amylase enzymes were evaluated. The content of gallic acid decreased after gastrointestinal digestion, while TPC, TFC, and AC significantly increased after each digestion phase. Overall, no significantly different enzyme inhibitions (p < 0.05) were observed among digested liqueurs, with moderate inhibition against acethylcholinesterase and tyrosinase (enzymes related with neurodegenerative diseases), and potent and low inhibitory capacities for α-glucosidase and α-amylase, respectively (ideal conditions employed in antidiabetic therapy). The study indicates that hydro-alcoholic infusion and maceration were the most appropriate methods to obtain liqueurs with higher values of the aforementioned parameters and safe levels of toxic furanics.