How do coffee substitutes compare to coffee? A comprehensive review of its quality characteristics, sensory characters, phytochemicals, health benefits and safety

Coffee substitutes: A review of the technology, characteristics, application, and future perspective

Despite being one of the most frequently consumed beverages worldwide, there are concerns that excessive consumption of coffee can have adverse effects, especially concerning the addictive and stimulating effects of the alkaloid caffeine, which contributes to coffee's popularity. It is known to increase the risk of hypertension and heart rate among predisposed individuals, adversely affecting the nervous system. Even though they differ in nature from those found in coffee, coffee substitutes can be considered economically and health-wise as a favorable alternative to natural coffee brews. This review summarizes the state-of-the-art varieties of plants used as coffee substitutes and discusses their production technology, chemical composition, nutritional properties, health benefits, economic challenges, and rationale for choosing the plant as a substitute for coffee. Various instant products and coffee substitute blends are also available on the market especially based on different kinds of plants and herbs like ginger, rye, date pits, quinoa, lupine, chicory, barley, rye, oak, and so on. These coffee substitutes have several advantages especially having no caffeine and containing different beneficial phytochemicals, although the results of the difference between the levels of harmful compounds in coffee and coffee substitutes were contradictory. Therefore, it is no wonder that the development of coffee substitutes, which are beverages that are able to mimic the taste and aroma of coffee, is on the rise at present.

Acrylamide and HMF occurrence and bioaccessibility in instant coffee and coffee substitutes. A study on isolated and milk-combined beverages

This research evaluated the occurrence and bioaccessibility of acrylamide and HMF in commercial instant coffees (IC) and coffee substitutes (CS), considering both isolated consumption and combination with milk. There were no significant differences in acrylamide content between IC and CS samples (median: 589 vs. 671 µg/kg), but higher variability was reported for CS, probably due to their varied composition (roasted cereals, nuts, honey, dehydrated fruits, and/or chicory). Acrylamide level were always below the EU benchmark for each category. HMF contents were similar between both groups (1354-5127 mg/kg for IC and 735-7134 mg/kg for CS; median: 2890 vs. 2960 mg/kg), with no clear ingredient relationship. Since IC consumption by the Spanish population is ten times higher than that of CS, exposure to acrylamide and HMF was higher from IC (6.8 vs. 1.07 ng/kg body weight/day for acrylamide; 39.1 vs. 4.2 µg/kg body weight/day for HMF). The standardized in vitro gastrointestinal digestion protocol (INFOGEST) was used. The gastrointestinal process reduced the bioaccessibility of acrylamide up to 27.2 % in IC and to 22.4 % in CS, regardless of the presence of milk. HMF bioaccessibility from IC significantly dropped after the gastrointestinal digestion, whereas it greatly increased for CS. The presence of milk did not affect HMF bioaccessibility. These results highlight the importance of assessing food bioaccessibility in typical consumption scenarios, providing a holistic view and a realistic evaluation of the potential risks associated with acrylamide and HMF exposure in the diet.

Valorization of baobab seeds (Adansonia digitata) as a coffee-like beverage: evaluation of roasting time on bioactive compounds

The baobab tree (Adansonia digitata) can be found in sub-Saharan Africa, and its fruit presents high nutritional value. However, baobab seeds are often discarded and their potential remains underutilized. This study aimed to investigate the effect of roasting time (30/55/80/105 min at 200 °C) on the physical-chemical properties of baobab seeds and the bioactive compounds in a coffee-like beverage. The results showed a decrease in moisture, Aw (water activity), and hardness of baobab seeds with increasing roasting time. These changes resulted from moisture loss, caramelization, and Maillard reactions, which also affected appearance when compared with unroasted baobab seeds. The pH of the beverage decreased to a value of around 6.01 after 105 min of roasting. The total phenolic content and antioxidant activity of the beverage increased with roasting time, reaching 851.2 mg GAE/100 g (after 80 min) and 18.9 mmol Fe2+/100 g (after 55 min), respectively. The caffeine content remained stable around 16 mg/100 g from 55 to 105 min, lower than that of unroasted coffee beans and decaffeinated coffee. These findings suggest the potential for valorizing baobab seeds in the development of a new coffee-like beverage with lower caffeine content.

The fate of quinolizidine alkaloids during the processing of lupins (Lupinus spp.) for human consumption

Lupin, a protein-rich grain legume, and products thereof, are becoming increasingly important in our diets. However, variable and high concentrations of quinolizidine alkaloids (QAs) may hamper this evolution. This study assessed the fate of QAs when processing Lupinus albus seeds and lupin-based foods, to give a first indication of the food industry's ability to sufficiently reduce the QA concentration. Typical unit processes, including toasting, dehulling, sterilization (sterilized jarred lupins), oven baking (cookies), frying (chips) and boiling in water (pasta), were simulated on lab-scale. A quantitative determination of five QAs and qualitative screening of other relevant QAs, in the derived fractions and lupin-based foods, was performed with a validated UHPLC-MS/MS and -HRMS method, respectively. Results revealed that the reduction in quinolizidine alkaloid content is highly dependent on the applied unit process, that QAs appear to be heat stabile, and that the depletion can be attributed to the leaching in cooking water.

Nutritional probing and storage stability of papaya jam supplemented with date pit powder

Jam Quality is a factor robustly influenced by storage conditions. The current research aimed to develop papaya jam with improved nutritional attributes, rheological profile, and shelf-life utilizing date pit powder as a functional ingredient. The effect of date pit powder on the formulated product's physicochemical, microbial, and organoleptic properties was analyzed. Results revealed that overall mineral profile (0.35-1.11%), crude fiber (0.56-2.01%), pH (3.51-3.70%), and antioxidant properties (22.97-30.67%) were significantly increased while water activity reduced (0.77-0.73). Moreover, date pit powder improved the color scores like a*(10.10-10.67), b* (8.13-8.78), L* (25.56-28.09), and textural attributes (Cohesiveness: 0.83-0.90; Firmness: 6.82-6.93) of functional papaya jam. Microbial count reduced from 3.60 × 10⁵-3.06 × 10⁵ cfu/ml by adding date pit powder and staying within the acceptable limit (4.13 × 10⁵-3.60 × 10⁵ cfu/ml) during 2-month storage at refrigeration. Organoleptic evaluation depicted that samples treated with date pit powder scored better than the control, and a sample with 75% pectin replacement was considered best.

Potential valorisation of baobab (Adansonia digitata) seeds as a coffee substitute: Insights and comparisons on the effect of roasting on quality, sensory profiles, and characterisation of volatile aroma compounds by HS-SPME/GC-MS

The seeds of Africa's majestic baobab are often discarded or poorly utilized. Few studies explored its potential as a coffee substitute, while the key volatile compounds are still unknown. These compounds were hypothesized to be responsible for baobab's sensory acceptance. In this study, the physicochemical, sensory, and key volatile composition of brews from coffee beans and baobab seeds subjected to different roasting conditions were reported. Roasting increases pH while reducing acidity, total soluble solids, lightness (L*), redness/greenness (a*), and yellowness/blueness (b*) in coffee and baobab brews. Phenolic contents increased significantly (p < 0.05) with increased roasting intensity in baobab while degrading in coffee. Significant variability of volatile composition existed among coffee and baobab matrices and the roasting conditions. Nevertheless, the presence of several key coffee odorants in baobab from pyrazines, phenols, and furans chemical families, owing to their odour active value ≥ 1, likely contributed to its sensory acceptance.

Metabolomics-Based Approach for Coffee Beverage Improvement in the Context of Processing, Brewing Methods, and Quality Attributes

Coffee is a worldwide beverage of increasing consumption, owing to its unique flavor and several health benefits. Metabolites of coffee are numerous and could be classified on various bases, of which some are endogenous to coffee seeds, i.e., alkaloids, diterpenes, sugars, and amino acids, while others are generated during coffee processing, for example during roasting and brewing, such as furans, pyrazines, and melanoidins. As a beverage, it provides various distinct flavors, i.e., sourness, bitterness, and an astringent taste attributed to the presence of carboxylic acids, alkaloids, and chlorogenic acids. To resolve such a complex chemical makeup and to relate chemical composition to coffee effects, large-scale metabolomics technologies are being increasingly reported in the literature for proof of coffee quality and efficacy. This review summarizes the applications of various mass spectrometry (MS)- and nuclear magnetic resonance (NMR)-based metabolomics technologies in determining the impact of coffee breeding, origin, roasting, and brewing on coffee chemical composition, and considers this in relation to quality control (QC) determination, for example, by classifying defected and non-defected seeds or detecting the adulteration of raw materials. Resolving the coffee metabolome can aid future attempts to yield coffee seeds of desirable traits and best flavor types.

Chemical Composition and Potential Biological Activity of Melanoidins From Instant Soluble Coffee and Instant Soluble Barley: A Comparative Study

In this work a comparative study of the chemical composition and potential biological activity of high molecular weight (HMW) melanoidins isolated from instant soluble coffee (ISC) and instant soluble barley (ISB) was performed. ISB HMW melanoidins were almost exclusively composed by an ethanol soluble (EtSn) melanoidin fraction composed by glucose (76% w/w) partially susceptible to in vitro digestion, whereas ISC was composed mainly by arabinogalactans (~41% w/w) and lower amounts of galactomannans (~14% w/w) presenting a range of ethanol solubilities and resistant to in vitro digestion. Melanoidins from ISC presented a significantly higher content of condensed phenolic compounds (17/100 g) when compared to ISB (8/100 g) showing also a higher in vitro scavenging of ABTS•+ (329 mmol Trolox/100 g vs. 124 mmol Trolox/100 g) and NO radicals (inhibition percentage of 57 and 26%, respectively). Nevertheless, ISB EtSn melanoidins presented, on average a higher inhibitory effect on NO production from LPS-stimulated macrophages. ISB melanoidins, up to 1 mg/mL, did not induce toxicity in Caco-2, HepG2 and RAW 264.7 cell lines while at the highest concentration ISC slightly reduced cell viability. Thus, consumption of a diet rich in ISC and ISB melanoidins may reduce the oxidative stress, the inflammatory levels and increase the protective effects against chronic inflammatory diseases.