Assessment of Concentrated Liquid Coffee Acceptance during Storage: Sensory and Physicochemical Perspective

Abstract

Concentrated liquid coffees (CLCs) refer to stored extracts stable at environmental temperature, used as ingredients in the retail market. Their low chemical stability affects the sensory profile. This study was performed in two CLCs, one without additives (BIB) and another with a mix of sodium benzoate and potassium sorbate additives (SD), stored at 25 °C for one year. Quantitative-Descriptive (QDA) and discriminant analyses permitted identifying the critical sensory attributes and their evolution over time. The concentrate without additives presented an acceptance limit of 196 days (evaluated at a 50% acceptance ratio), while the additives increased the shelf life up to 226 days (38.9% improvement). The rejection was related to a decreased aroma, increased acidity, and reduced bitterness. A bootstrapped feature selection version of Partial Least Square analysis further demonstrated that reactions of 5-caffeoylquinic acid (5CQA) and 3,5-dicaffeoylquinic acid (3,5diCQA) could cause changes in the aroma at the first degradation stage. In the following stages, changes in fructose and stearic acid contents, a key indicator of acceptance for both extracts possibly related to non-enzymatic reactions involving fructose and other compounds, might affect the bitterness and acidity. These results provided valuable information to understand flavor degradation in CLCs.

Exploring Chemical Markers Related to the Acceptance and Sensory Profiles of Concentrated Liquid Coffees: An Untargeted Metabolomics Approach

“…Consequently, rejection of CLCs might be strongly associated with the degradation of CGAs that results in the release of ferulic, quinic, and caffeic acids to start three degradation pathways that promote changes in some of the sensory attributes, such as aroma and acidity. These results agree with those presented in a previous work [21] and by other studies [28,30,34].…”

“…In recent years, food metabolomics has been applied to all stages of food systems, from farms to industrial food processing and food intake [19]. Untargeted metabolomics analyses of coffee have been carried out to identify the coffee's origin [11], correlation with sensory quality before roasting [12], roasting process [4,6,20,21], beverage and extraction methods [11,20], and instant coffees [6]. However, there have not been enough metabolomics studies to find the chemical markers that are associated with sensory rejection of coffee drinks from liquid coffee concentrates (CLCs) that have spent time in storage.…”

“…However, there have not been enough metabolomics studies to find the chemical markers that are associated with sensory rejection of coffee drinks from liquid coffee concentrates (CLCs) that have spent time in storage. In our previous paper, we performed a targeted analysis to describe the dependence of CLC acceptance based on decrement of the sensory quality and how these attributes correlate with changes in the chlorogenic acid and carbohydrate contents [21].…”

Physicochemical properties and storage stability of Turkish coffee fortified with apricot kernel powder

“…Similar to the current study results, many studies with coffee have reported that specific sensory characteristics of coffee may remain stable during storage. Although changes are observed in sensory properties in long‐term storage such as 9 and 12 months, it is known that many sensory properties can remain stable in short‐term storage such as 30 and 60 days (Kreuml et al, 2013; Rendón et al, 2014; Quintero et al, 2021).…”