The study of galactomannans with different molecular weights and their ability to form microparticles suitable for pulmonary delivery.

The influence of locust bean gum (LBG) galactomannans (GMs) molecular weight (Mw) to assemble microparticulate systems was evaluated, and carriers for deep lung delivery were developed. A commercial batch of LBG with a mannose/galactose (M/G) ratio of 2.4 (batch 1) was used to study the influence of different microwave partial acid hydrolysis conditions on carbohydrate composition, glycosidic linkages, and aqueous solutions viscosity. The microwave treatment did not affect the composition, presenting 4-Man (36-42 %), 4,6-Man (27-35 %), and T-Gal (24-25 %) as the main glycosidic linkages. Depolymerization led to a viscosity reduction (≤0.005 Pa·s) with no major impact on polysaccharide debranching. The structural composition of the LBG galactomannans were further elucidated with sequence-specific proteins using carbohydrate microarray technologies. A second batch of LBG (M/G 3.3) was used to study the impact of GMs with different Mw on microparticle assembling, characteristics, and insulin release kinetics. The low-Mw GMs microparticles led to a faster release (20 min) than the higher-Mw (40 min) ones, impacting the release kinetics. All microparticles exhibited a safety profile to cells of the respiratory tract. However, only the higher-Mw GMs allowed the assembly of microparticles with sizes suitable for this type of administration.

Mycotoxins' Prevalence in Food Industry By-Products: A Systematic Review.

The recovery of biomolecules from food industry by-products is of major relevance for a circular economy strategy. However, by-products' contamination with mycotoxins represents a drawback for their reliable valorization for food and feed, hampering their application range, especially as food ingredients. Mycotoxin contamination occurs even in dried matrices. There is a need for the implantation of monitoring programs, even for by-products used as animal feed, since very high levels can be reached. This systematic review aims to identify the food by-products that have been studied from 2000 until 2022 (22 years) concerning mycotoxins' contamination, distribution, and prevalence in those by-products. PRISMA ("Preferred Reporting Items for Systematic Reviews and MetaAnalyses") protocol was performed via two databases (PubMed and SCOPUS) to summarize the research findings. After the screening and selection process, the full texts of eligible articles (32 studies) were evaluated, and data from 16 studies were considered. A total of 6 by-products were assessed concerning mycotoxin content; these include distiller dried grain with solubles, brewer's spent grain, brewer's spent yeast, cocoa shell, grape pomace, and sugar beet pulp. Frequent mycotoxins in these by-products are AFB1, OTA, FBs, DON, and ZEA. The high prevalence of contaminated samples, which surpasses the limits established for human consumption, thus limiting their valorization as ingredients in the food industry. Co-contamination is frequent, which can cause synergistic interactions and amplify their toxicity.

Polysaccharide-Based Carriers for Pulmonary Insulin Delivery: The Potential of Coffee as an Unconventional Source.

Non-invasive routes for insulin delivery are emerging as alternatives to currently painful subcutaneous injections. For pulmonary delivery, formulations may be in powdered particle form, using carriers such as polysaccharides to stabilise the active principle. Roasted coffee beans and spent coffee grounds (SCG) are rich in polysaccharides, namely galactomannans and arabinogalactans. In this work, the polysaccharides were obtained from roasted coffee and SCG for the preparation of insulin-loaded microparticles. The galactomannan and arabinogalactan-rich fractions of coffee beverages were purified by ultrafiltration and separated by graded ethanol precipitations at 50% and 75%, respectively. For SCG, galactomannan-rich and arabinogalactan-rich fractions were recovered by microwave-assisted extraction at 150 °C and at 180 °C, followed by ultrafiltration. Each extract was spray-dried with insulin 10% (w/w). All microparticles had a raisin-like morphology and average diameters of 1-5 µm, which are appropriate for pulmonary delivery. Galactomannan-based microparticles, independently of their source, released insulin in a gradual manner, while arabinogalactan-based ones presented a burst release. The microparticles were seen to be non-cytotoxic for cells representative of the lung, specifically lung epithelial cells (A549) and macrophages (Raw 264.7) up to 1 mg/mL. This work shows how coffee can be a sustainable source of polysaccharide carriers for insulin delivery via the pulmonary route.

Polysaccharide-based formulations as potential carriers for pulmonary delivery - A review of their properties and fates.

Polysaccharides can be elite carriers for therapeutic molecules due to their versatility and low probability to trigger toxicity and immunogenic responses. Local and systemic therapies can be achieved through particle pulmonary delivery, a promising non-invasive alternative. Successful pulmonary delivery requires particles with appropriate flowability to reach alveoli and avoid premature clearance mechanisms. Polysaccharides can form micro-, nano-in-micro-, and large porous particles, aerogels, and hydrogels. Herein, the characteristics of polysaccharides used in drug formulations for pulmonary delivery are reviewed, providing insights into structure-function relationships. Charged polysaccharides can confer mucoadhesion, whereas the ability for specific sugar recognition may confer targeting capacity for alveolar macrophages. The method of particle preparation must be chosen considering the properties of the components and the delivery device to be utilized. The fate of polysaccharide-based carriers is dependent on enzyme-triggered hydrolytic and/or oxidative mechanisms, allowing their complete degradation and elimination through urine or reutilization of released monosaccharides.

Insights on Single-Dose Espresso Coffee Capsules' Volatile Profile: From Ground Powder Volatiles to Prediction of Espresso Brew Aroma Properties.

Single-dose coffee capsules have revolutionized the coffee market, fueling espresso coffee popularity and offering access to a wide selection of coffee blends. Nevertheless, scarce information related to coffee powder and brew's combined volatile characterization is available. In this study, it is hypothesized that coffee brew aroma characteristics can be predicted based on coffee powder's volatile composition. For this, headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection (GC × GC-ToFMS) was used. The data were combined via chemometric tools to characterize in depth the volatile composition of eight blends of capsule-coffee powder and respective espresso brews, simulating the consumer's perception. A total of 390 volatile compounds were putatively identified, 100 reported for the first time in roasted coffee or brews. Although the same chemical families were determined among the coffee powders and espresso brews, a different volatile profile was determined for each matrix. The Pearson correlation of coffee powders and respective brews allowed to identify 15 volatile compounds, mainly terpenic and esters recognized by their pleasant notes, with a strong relationship between the amounts present in both matrices. These compounds can be key markers to predict the volatile aroma potential of an espresso brew when analyzing the coffee powder.

In vitro immunomodulatory activity of water-soluble glucans from fresh and dried Longan (Dimocarpus longan Lour.).

Longan (Dimocarpus longan Lour.) is a seasonal tropical fruit used by Chinese medicine in both fresh and dried pulp forms. Their polysaccharides have been reported to have biological activity. However, their composition and immune activity have not yet been disclosed. To fulfil this aim, hot water-soluble polysaccharides of fresh and dried longan pulp were fractionated according to their molecular weight by ultrafiltration (10, 50, 100 kDa cut off). The main polysaccharides recovered were 1,6-linked glucans branched at O-3 (4-8%), O-2 (1%), O-2,4 (0.1%), and O-3,4 (0.1%). The drying process promotes the solubility of the polysaccharides. These glucans from fresh and dried longan pulp have immunomodulatory activity, shown by in vitro phagocytosis, NO, TNF-α, and IL-6 macrophages production assays. They showed also to inhibit the inflammatory response induced by LPS. The immunological activity of these glucans seems to have different responses dependent on their molecular weight, related to the immune regulatory pathways.

Role of Coffee Caffeine and Chlorogenic Acids Adsorption to Polysaccharides with Impact on Brew Immunomodulation Effects.

Coffee brews have High Molecular Weight (HMW) compounds with described immunostimulatory activity, namely polysaccharides and melanoidins. Melanoidins are formed during roasting and are modified during brews technological processing. In addition, brews have Low Molecular Weight (LMW) compounds, namely free chlorogenic acids and caffeine, with well-known anti-inflammatory properties. However, this study shows that both espresso and instant coffee brews did not present immunostimulatory neither anti-inflammatory in vitro activities. It is possible that the simultaneous existence of compounds with antagonistic effects can mitigate their individual effects. To test this hypothesis, an ultrafiltration separation process was applied, studying the behavior of coffee brews' HMW on retention of LMW compounds. Several ultrafiltration sequential cycles were required to separate retentates from LMW compounds, suggesting their retention. This effect was higher in instant coffee, attributed to its initial higher carbohydrate content when compared to espresso. Separation of HMW and LMW compounds boosted their immunostimulatory (6.2-7.8 µM nitrites) and anti-inflammatory (LPS induced nitrite production decrease by 36-31%) in vitro activities, respectively. As coffee anti-inflammatory compounds are expected to be first absorbed during digestion, a potential in vivo fractionation of LMW and HMW compounds can promote health relevant effects after coffee intake.

Carbohydrates as targeting compounds to produce infusions resembling espresso coffee brews using quality by design approach.

All coffee brews are prepared with roasted coffee and water, giving origin to espresso, instant, or filtered coffee, exhibiting distinct physicochemical properties, depending on the extraction conditions. The different relative content of compounds in the brews modulates coffee body, aroma, and colour. In this study it was hypothesized that a coffee infusion allows to obtain extracts that resemble espresso coffee (EC) physicochemical properties. Carbohydrates (content and composition) were the target compounds as they are organoleptically important for EC due to their association to foam stability and viscosity. The freeze-drying of the extracts allowed better dissolution properties than spray-drying. Instant coffee powders were obtained with chemical overall composition resembling espresso, although with lower lipids content. The extracts were able to produce the characteristic foam through CO2 injection or salts addition. Their redissolution at espresso concentration allowed a viscosity, foamability and volatile profile representative of an espresso coffee, opening new exploitation possibilities.

In Vitro Hypocholesterolemic Effect of Coffee Compounds.

(1) Background: Cholesterol bioaccessibility is an indicator of cholesterol that is available for absorption and therefore can be a measure of hypocholesterolemic potential. In this work, the effect of commercial espresso coffee and coffee extracts on cholesterol solubility are studied in an in vitro model composed by glycodeoxycholic bile salt, as a measure of its bioaccessibility. (2) Methods: Polysaccharide extracts from coffees obtained with different extraction conditions were purified by selective precipitation with ethanol, and their sugars content were characterized by GC-FID. Hexane extraction allowed us to obtain the coffee lipids. Espresso coffee samples and extracts were tested regarding their concentration dependence on the solubility of labeled 13C-4 cholesterol by bile salt micelles, using quantitative 13C NMR. (3) Results and Discussion: Espresso coffee and coffee extracts were rich in polysaccharides, mainly arabinogalactans and galactomannans. These polysaccharides decrease cholesterol solubility and, simultaneously, the bile salts' concentration. Coffee lipid extracts were also found to decrease cholesterol solubility, although not affecting bile salt concentration. (4) Conclusions: Coffee soluble fiber, composed by the arabinogalactans and galactomannans, showed to sequester bile salts from the solution, leading to a decrease in cholesterol bioaccessibility. Coffee lipids also decrease cholesterol bioaccessibility, although the mechanism of action identified is the co-solubilization in the bile salt micelles. The effect of both polysaccharides and lipids showed to be additive, representing the overall effect observed in a typical espresso coffee. The effect of polysaccharides and lipids on cholesterol bioaccessibility should be accounted on the formulation of hypocholesterolemic food ingredients.

Impact of microwave-assisted extraction on roasted coffee carbohydrates, caffeine, chlorogenic acids and coloured compounds.

Microwave-assisted extraction (MAE) allows to quickly achieve soluble compounds from solid matrices due to the promotion of temperatures higher than the solvent (atmospheric) boiling point, once a closed-vessel system is used for operating at high pressure. In this study, the feasibility of MAE for producing high yield coffee extracts with properties that allow their commercial application was tested through a quality by design approach. It was studied the influence of time of extraction (1, 5.5, 10 min), temperature (120, 150, 180 °C) and the mass-to-volume (m/V) ratio (2, 4, 6 g/60 mL) in the overall extraction yield (24-47%, w/w), carbohydrates content (18-43%, w/w), sugars composition, caffeine (4-7%, w/w), 5-caffeoylquinic acid (1-2%, w/w), colour and antioxidant activity of the extracts. FTIR analysis was used to study the resemblance of coffee extracts and commercial instant coffee. MAE allowed overall extraction yields considerably higher than the home brewing methods, mainly when performed at 180 °C, with a substantial increase in arabinogalactans (AG) extraction associated to higher temperatures. Temperature exerted a crucial role in coffee extracts differentiation, although time and m/V ratio also lead to different values in the responses. Under a circular economy concept, MAE was able to produce extracts that can be used as defined food/brew ingredients and provides a galactomannan and cellulose rich residue that can also be valued as a source of dietary fibre.

Data on yields, sugars and glycosidic-linkage analyses of coffee arabinogalactan and galactomannan mixtures and optimization of their microwave assisted extraction from spent coffee grounds.

The data presented here are related to the research paper entitled "Structural features of spent coffee grounds water-soluble polysaccharides: towards tailor-made microwave assisted extractions" [1]. Microwave assisted extraction conditions were applied to spent coffee grounds for recovery of polysaccharides, namely arabinogalactans and galactomannans. Following an experimental design testing temperature, time, and alkali conditions as influence factors during microwave assisted extraction, this article reports the response data for the total extracted mass, sugars yield (including arabinogalactans and galactomannans total content, and mass ratio), and structural features (including degree of polymerization and degree of branching) for each set of operating conditions. In addition, it provides gas chromatography-mass spectrometry (GC-MS) chromatograms (and respective GC-MS spectra) of arabinogalactan and galactomannan mixtures with different structural features corresponding to representative microwave treatment conditions.

Structural features of spent coffee grounds water-soluble polysaccharides: Towards tailor-made microwave assisted extractions.

This work studies the microwave-assisted extraction conditions for recovery of polysaccharides from spent coffee grounds, including their effect on arabinogalactans and galactomannans polymerization and branching structural features. Temperature (140, 170, and 200 °C) has the most significant impact on total extracted mass (ηtotal soluble solids) and sugars yield (ηsugars), arabinogalactans (ηAG) and galactomannans (ηGM), and polysaccharide mass ratio (ηAG/ηGM). Time (2, 5, and 10 min) and alkali (diluted 0.1 M NaOH) treatments have less influence. Alkali treatment and shorter time (2 min) provided a protective effect against polysaccharides degradation. At 170 °C, the yield of arabinogalactans was found to be significantly higher than that of galactomannans (ηAG/ηGM >1). Increasing temperature to 200 °C leads to decrease the polymerization of polysaccharides, promoting the formation of debranched polysaccharides and oligosaccharides. This study shows that the optimum conditions for polysaccharides extraction cannot be selected only by mass yield but need to be defined according to the desired structural features for the specific applications.

Structural polymeric features that contribute to in vitro immunostimulatory activity of instant coffee.

An instant coffee fraction, rich in arabinogalactans, obtained by ultrafiltration, using 1 and 5kDa membranes, has previously shown in vitro stimulatory activity on BALB/c mice spleen B lymphocytes. The compounds inducing lymphocytic activation were shown to elute, mainly near the void volume by size-exclusion chromatography, using Bio-Gel P6 (1-6kDa). Treatment of the compounds with chymotrypsin, a digestive protease, did not affect the induced B lymphocyte activation. On the contrary, hydrolysis with an α-l-arabinofuranosidase, removing single terminally-linked arabinose residues, decreased the extent of B cell activation. The immunostimulatory activity of these compounds was also observed by in vitro experiments, using bone marrow-derived macrophages and dendritic cells as responders. Altogether, these results show the relevance of single arabinose residues, present at the non-reducing end of polymeric compounds, to the coffee stimulatory activity in cells mediating innate and acquired immunity.