Black carrot has been attracting increasing thanks to its high bioactive compound content. This study presents the polyphenol bio-accessibility of black carrot and two derived products (black carrot snack (BC snack) and black carrot seasoning (BC seasoning)) after in vitro gastrointestinal digestion and colonic fermentation. Additionally, antioxidant activity was measured by 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. Nine flavonoids and eight anthocyanins were determined by ultra high-performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) analysis, the predominant compounds being the hydroxycinnamic acids 3-O-feruloylquinic acid, 4-O-feruloylquinic acid and chlorogenic acid. The BC snack (108 µmol/g DW) presented the highest total polyphenol content, followed by BC seasoning (53 µmol/g DW) and black carrot (11.4 µmol/g DW). The main polyphenols still bio-accessible after in vitro digestion were the hydroxycinnamic acids, with mean recovery rates of 113 % for black carrot, 69% for BC snack and 81% for BC seasoning. The incubation of black carrot and its derived products with human faecal bacterial resulted in the complete degradation of anthocyanins and in the formation of mainly 3-(4′-hydroxyphenyl)propanoic acid as the major catabolic event. In conclusion, our results suggest that the black carrot matrix impacts significantly affects the bio-accessibility of polyphenols and, therefore, their potential health benefits.
Cocoa (Theobroma cacao L.) is one of the most widely consumed edible seeds in the world affected by on-farm processing. This study investigated the effect of different drying techniques, namely oven drying (OD), sun drying (SD), and a modification of sun drying using black plastic sheeting (SBPD), on the volatile profile of fine-flavor and bulk cocoa varieties analyzed by HS-SPME-GC-MS. A total of sixty-four volatile compounds were identified in fresh and dried cocoa. As expected, the volatile profile was clearly modified after the drying step, showing strong differences among cocoa varieties, this factor and its interaction with the drying technique having greater influence according to the ANOVA simultaneous component analysis. A principal component analysis revealed a close relationship between the volatile content of bulk cocoa samples dried by the OD and SD techniques, whereas slight volatile modifications were perceived among fine-flavor samples dried using the three different techniques under study. Overall, the results provide the basis for the potential application of the simplest inexpensive SBPD technique in order to accelerate the drying process of sun drying and produce cocoa with similar (fine-flavor cocoa) or improved (bulk cocoa) aromatic quality to that formed using the traditional SD or the small-scale OD.
The banana is a tropical fruit characterized by its composition of healthy and nutritional compounds. This fruit is part of traditional Ecuadorian gastronomy, being consumed in a wide variety of ways. In this context, unripe Red Dacca banana samples and those submitted to different traditional Ecuadorian heating treatments (boiling, roasting, and baking) were evaluated to profile their phenolic content by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) and the antioxidant activity by ORAC, ABTS, and DPPH assays. A total of sixty-eight phenolic compounds were identified or tentatively identified in raw banana and treated samples, highlighting the content in flavonoids (flavan-3-ols with 88.33% and flavonols with 3.24%) followed by the hydroxybenzoic acid family (5.44%) in raw banana samples. The total phenolic compound content significantly decreased for all the elaborations evaluated, specifically from 442.12 mg/100 g DW in fresh bananas to 338.60 mg/100 g DW in boiled (23.41%), 243.63 mg/100 g DW in roasted (44.90%), and 109.85 mg/100 g DW in baked samples (75.15%). Flavan-3-ols and flavonols were the phenolic groups most affected by the heating treatments, while flavanones and hydroxybenzoic acids showed higher stability against the heating treatments, especially the boiled and roasted samples. In general, the decrease in phenolic compounds corresponded with a decline in antioxidant activity, evaluated by different methods, especially in baked samples. The results obtained from PCA studies confirmed that the impact of heating on the composition of some phenolic compounds was different depending on the technique used. In general, the heating processes applied to the banana samples induced phytochemical modifications. Even so, they remain an important source of bioactive compounds for consumers.
Dry-cured tuna is a traditional product manufactured in the Mediterranean region of Spain, known as mojama. The traditional salting-drying elaboration process attributes new organoleptic characteristics to the final product, changing its flavor, color, and nutritional value. This study aimed to evaluate the changes in physicochemical, biochemical, and microbiological parameters taking place during the process. The physicochemical parameters were affected by the processing steps (salting, salt-washing, and drying), except for total acidity and pH. The water activity value and relative moisture percentage decreased to 0.86 and 33.03%, respectively. Moreover, the addition of salt and the drying step increased the water-holding capacity. The lipid oxidation values increased from raw tuna loins to the final product (1.37 vs. 5.56 mg malondialdehyde/kg). Moreover, the total volatile basic nitrogen values increased in the final product, fundamentally due to the concentration effect caused by the water loss, although may also be due to the degradation of proteins during processing. The microbiological analysis showed that the values obtained in the dry-cured tuna were below the limits established by the reference regulation for dry-cured fish products.
Dry-cured tuna products exhibit unique aroma characteristics appreciated by local consumers, particularly in the southern Iberian Peninsula. In the present study, headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC/MS) was used to identify and quantify volatile organic compounds (VOCs), establishing a volatile fingerprint of dry-cured tuna throughout the manufacturing process. Unsupervised (PCA) and supervised (PLS-DA and sPLS-DA) multivariate statistical methods were applied to visualise, group, and classify the samples. A total of fifty-four VOCs were identified across the four steps involved in processing the final product. The ML-PLS-DA model demonstrated excellent discrimination (R2 = 0.912, Q2 = 0.878, and Accuracy = 1) for the samples. Additionally, ML-sPLS-DA was conducted to screen various VOC metabolites in the samples after both the salting and salt-washing steps; the levels of eighteen VOCs changed significantly (VIP > 1; p < 0.05). These results provide a theoretical basis for determining flavour formation and quality control in the traditional dry-curing process of tuna.
Agricultural diversification represents an important strategy for promoting sustainability and resilience in rural regions. Goji berries (Lycium barbarum) have emerged as a promising alternative crop due to their high nutritional and functional potential. In this sense, the search for new crops to diversify the production in southwestern Spain is of main interest for farmers to adapt their productions to consumers claims and to climate change, having alternatives to the classical crops (olives, grapes for wine, etc.). This study evaluated several quality related parameters of three goji berry varieties cultivated in the southwest of Spain. Texture profile analysis (TPA) and puncture tests revealed varietal differences in firmness, cohesiveness, and springiness, influenced by genotype and harvesting time. Other morphological and quality parameters such as moisture, total soluble solids, titratable acidity and color were also affected. Significant differences in antioxidant capacity (ABTS and DPPH assays) were found among the varieties and harvesting times, with NQ7 exhibiting the highest values. Phenolic compounds were identified and quantified by LC–HRMS/MS, detecting 33 compounds, with most belonging to the hydroxycinnamic acids, flavonols and flavanones families. NQ7 presented the highest total phenolic content (74.787 mg/100 g DW), with rutin, coumaric acid derivatives, and naringenin as major contributors. The correlation analysis confirmed a strong relationship between total phenolic content and antioxidant capacity. Overall, the results indicated that goji berries grown in southwestern Spain exhibited favorable quality and bioactive profiles, supporting their suitability for sustainable production and commercialization, including further applications as functional food ingredients.