Evaluating the effect of roasting on coffee lipids using a hybrid targeted-untargeted NMR approach in combination with MRI

Revealing the dynamic changes of lipids in coffee beans during roasting based on UHPLC-QE-HR-AM/MS/MS

Coffee is popular worldwide and its consumption is increasing in recent years. Although mass spectrometry-based lipidomics approaches have been prevalent, their application in studies related to detailed information and dynamic changes in lipid composition during coffee bean roasting is still limited. The aim of this study was to investigate the dynamic changes in coffee bean lipids during the roasting process. The lipid classes and lipid molecular species in coffee beans were characterized by lipidomic analysis combined with chemometrics. A total of 12 lipid classes and 105 lipid molecular species were identified and quantified. Triacylglycerols (TAG) was the most abundant lipid class in both green beans and roasted beans. The content of phosphatidylethanolamine (PE) and lysophosphatidylethanolamine (LPE) in green beans was obviously higher than that in roasted beans. Other phospholipids, such as phosphatidylinositol (PI), lysophosphatidylinositol (LPI), phosphatidylcholine (PC), lysophophatidylcholine (LPC) and phosphatidic acid (PA), showed a tendency to increase at the beginning of roasting, then decreased gradually. Several differential lipid molecule species, for instance, PE (16:0_18:2), PC (18:2_18:2) were significantly down-regulated, and PI (18:1_18:2) was significantly up-regulated. This study provided a scientific basis for the change of coffee bean lipids during the roasting process.

Diterpenes stability of commercial blends of roasted and ground coffees packed in copolymer coupled with aluminium and eco-friendly capsules

Diterpenes are group of compounds of the terpenic fraction of roasted coffee and account for about 7-20 % (w/w) of the lipid fraction. Several parameters can influence their occurrence in coffee beans and beverages including species and post-harvest processing. Diterpenes in coffee have been studied extensively, but to the best of the authors' knowledge, there is no information in the literature on their stability over time. Coffee is a relatively stable product under optimal temperature, humidity and oxygen conditions. However, during storage it can undergo a series of chemical and physical reactions that alter its flavour and lead to rancidity, mainly due to the oxidative reactions that take place on the lipid fraction. In this study, the effect of long-term storage on the diterpene content of different commercial coffee blends and packaging is analysed and critically discussed. The Results show that the storage influences the internal environment of the capsules with an increase in moisture and a decrease in pH favouring more reactive conditions, especially for Eco capsules. Relative stability over time is observed for cafestol and kahweol. dehydro derivatives show a degradation up to T60 independently on the blends and packaging, which is not related to their precursors. The permeability of packaging and blends affect the modification of these components: while a drastic oxidation process takes place in Arabica eco compatible capsules (PC) when acidity and moisture increase, in Arabica/Robusta eco compatible capsules (IC) as well as in Arabica/Robusta and Arabica standard capsules (IS and PS) the peroxides tend to increase resulting in an autocatalytic propagation.

Two Ways to Achieve the Same Goal-Two Validated Quantitative NMR Strategies for a Low-Abundance Natural Product in Standardized Extracts: The Case of Hepatodamianol in Turnera diffusa

The quantification of low-abundance secondary metabolites in plant extracts is an analytical problem that can be addressed by different analytical platforms, the most common being those based on chromatographic methods coupled to a high-sensitivity detection system. However, in recent years nuclear magnetic resonance (NMR) has become an analytical tool of primary choice for this type of problem because of its reliability, inherent simplicity in sample preparation, reduced analysis time, and low solvent consumption. The versatility of strategies based on quantitative NMR (qNMR), such as internal and external standards and electronic references, among others, and the need to develop validated analytical methods make it essential to compare procedures that must rigorously satisfy the analytical well-established acceptance criteria for method validation. In this work, two qNMR methods were developed for the quantification of hepatodamianol, a bioactive component of T. diffusa. The first method was based on a conventional external standard calibration, and the second one was based on the pulse length-based concentration determination (PULCON) method using the ERETIC2 module as a quantitation tool available in TopSpin software. The results show that both procedures allow the content of the analyte of interest in a complex matrix to be determined in a satisfactory way, under strict analytical criteria. In addition, ERETIC2 offers additional advantages such as a reduction in experimental time, reagent consumption, and waste generated.

A Systematic Mapping Study of Coffee Quality throughout the Production-to-Consumer Chain

Coffee is one of the most consumed beverages in the world and is crucial in the economy of many developing countries. The search to improve coffee quality comes from many fronts, as do the many ways to measure quality and the factors that affect it. Several techniques are used to measure the different metrics to assess coffee quality, across different types of coffee samples and species, and throughout the entire process from farm to cup. In this work, we conducted a systematic mapping study of 1,470 articles to identify the aspects of quality that are the most important in the scientific literature to evaluate coffee throughout the processing chain. The study revealed that cup quality and biochemical composition are the most researched quality attributes. The main objective of the reviewed studies is the correlation between different quality measurements. The most used techniques are the analytical chemistry methods. The most studied species is Coffea arabica. The most used sample presentation is green coffee. The postharvest stage is the most researched, in which quality control receives more attention. In the preharvest stage, management practices stand out. Finally, the most used type of research was the evaluation research.

Safest Roasting Times of Coffee To Reduce Carcinogenicity

ABSTRACT

Roasting coffee results in not only the creation of carcinogens such as acrylamide, furan, and polycyclic aromatic hydrocarbons but also the elimination of carcinogens in raw coffee beans, such as endotoxins, preservatives, or pesticides, by burning off. However, it has not been determined whether the concentrations of these carcinogens are sufficient to make either light or dark roast coffee more carcinogenic in a living organism. An Ames test was conducted on light, medium, and dark roast coffee from three origins. We found that lighter roast coffee shows higher mutagenicity, which is reduced to the control level in dark roast coffee varieties, indicating that the roasting process is not increasing mutagenic potential but is beneficial to eliminating the existing carcinogens in raw coffee beans. This result suggests that dark roast coffee is safer and promotes further studies of the various carcinogens in raw coffee that have been burned off.

HIGHLIGHTS

Microbial fermentation affects sensorial, chemical, and microbial profile of coffee under carbonic maceration

In view of the possibility of diversifying metabolic routes promoted by fermentation, this study proposed a new processing method for coffee, which consists of adapting a technique already consolidated in winemaking, carbonic maceration. The assay occurred under anaerobic conditions with different time and temperature fermentation. The aim of this study was to determine the differences in coffee characteristics (sensorial, chemical, and microbial) after carbonic maceration and fermentation. Specialty Coffee Association protocol, nuclear magnetic resonance, and denaturing gradient gel electrophoresis were used in these analyzes. A significant functional relationship between global score and temperature (38 °C), for the fermentation time of 96 h was observed. Bacterial diversity and sensory characteristics had a positive correlation. Furthermore, trigonelline, formic acid, hydroxymethylfurfural, lipids, and γ-butyrolactone also contributed to score and sensory quality of coffee beverage. Thus, our data show consistent factors to infer on the microbiological action on the sensory quality of coffee beverage.

New trends in coffee diterpenes research from technological to health aspects

The coffee oil is rich in diterpenes, mainly cafestol and kahweol, which are predominantly present in the esterified form with different fatty acids. Despite their beneficial effects including anti-angiogenic and anti-carcinogenic properties, they have been also associated with negative consequences such as elevation of blood cholesterol. Considering the coffee, it is an important human beverage with biological effects, including potentially health benefits or risks. Therefore, it may have important public health implications due to its widespread massive consumption, with major incidence in the varieties Arabica and Robusta. According to literatures, cafestol (182-1308 mg/100 g), kahweol (0-1265 mg/100 g) and 16-O-methycafestol (0-223 mg/100 g) are the main diterpenes in green and roasted coffee beans. Nevertheless, the coffee species, genetic background, and technological parameters like roasting and brewing have a clear effect on coffee diterpene content. Besides that, bibliographic data indicated that limited studies have specifically addressed the recent analytical techniques used for determination of this class of compounds, being HPLC and GC the most common approaches. For these reasons, this review aimed to actualize the occurrence and the profile of diterpenes in coffee matrices, focusing on the effect of species, roasting and brewing and on the other hand, introduce the current state on knowledge regarding coffee diterpenes determination which are nowadays highly regarded and widely used. In general, since diterpenes exhibit different health effects depending on their consumption dosage, several parameters needs to be carefully analyzed and considered when comparing the results.