Elucidation of Volatiles, Anthocyanins, Antioxidant and Sensory Properties of cv. Caner Pomegranate (Punica granatum L.) Juices Produced from Three Juice Extraction Methods

Effects of juicing methods on the bioactive compounds and flavor quality of 'Black-seed' pomegranate from three producing areas

BACKGROUND

Color, nutrients and flavor are the key characteristics of pomegranate juice, but they are susceptible to processing methods and raw materials. In this study, the effects of aril juicing and whole fruit juicing methods on the composition of 'Black-seed' pomegranate juice from three producing areas were studied, including physicochemical parameters, color attributes, organic acids, sugars, phenolic compounds, and volatile compounds.

RESULTS

The whole fruit juicing method resulted in higher juice yields of pomegranate fruit with 69.01-72.59%, hue angle values were 5.95-6.45°, and the juice remained red. The highest level of citric acid (21.21 g L-1 ), total acids (24.78 g L-1 ), and total anthocyanin content (435.59 mg L-1 ) were found in whole fruit juice, and seven tannins were detected. The most abundant volatile compounds were (Z)-3-hexen-1-ol and 1-hexanol in all juice samples, with alcohol content increased and aldehydes content decreased by whole fruit juicing. Principal component analysis revealed that the 24 indexes (variable important in projection >1) clearly distinguished juice samples obtained by two juicing methods, with ellagic acid hexoside, (E)-2-heptenal, (+)-catechin, and octanoic acid having the best discriminatory potential.

CONCLUSION

Overall, the effects of juicing method on 'Black-seed' pomegranate juice were greater than those of raw-material-producing areas. These results confirmed the potential for using the whole 'Black-seed' pomegranate for processing, and also provided a theoretical basis for the healthy product development and utilization of dark-color pomegranate varieties. © 2023 Society of Chemical Industry.

Probiotic yeast Saccharomyces cerevisiae Az-12 isolated from pomegranate juice presented inhibitory effects against pathogenic bacteria

The potential probiotic yeast was isolated from the Kyzyl Anor pomegranate variety growing in the Turkestan region (Kazakhstan). The yeast strain was identified as Saccharomyces cerevisiae Az-12. Molecular genetic identification was carried out using the Sanger sequencing method. The degree of homology of the S. cerevisiae Az-12 strain with the strain MH608341.1 Saccharomyces cerevisiae isolate extr03 was 99.65%. Antagonistic effect of the yeast against pathogenic bacteria was confirmed according inhibition zones for Staphylococcus aureus 13.5 ± 0.05 mm; the inhibition zones for Escherichia coli 12.8 ± 0.05 mm; and 10.7 ± 0.05 mm for Pseudomonas aeruginosa. Scanning microscopy of S. cerevisiae Az-12 and S. aureus confirmed the adhesive ability of the yeast cell surface to S. aureus. S. cerevisiae Az-12 were chosen as the most promising, as they are able to quickly ferment juices. Functional drinks containing pomegranate juice and yeast with a probiotic effect can be considered as a useful synbiotic product formulation.

Flavoromics Approach in Critical Aroma Compounds Exploration of Peach: Correlation to Origin Based on OAV Combined with Chemometrics

It is essential to seek the critical aroma compounds to identify the origins of peach as well as provide a guidance for quality evaluation. In this study, the peach was characterized by HS-SPME/GC-MS. Subsequently, the odor activity value (OAV) was calculated to specify the primary aroma-active compounds. Afterwards, the chemometrics methods were employed to explore the potentially critical aroma on the basis of p value, fold change (FC), S-plot, jack-knifing confidence interval, variable importance for projection (VIP), and the Shared and Unique Structures (SUS) plots. As a result, five compounds (methyl acetate, (E)-hex-2-enal, benzaldehyde, [(Z)-hex-3-enyl] acetate, and 5-ethyloxolan-2-one) were considered as critical aromas. Moreover, the multi-classification model was developed with an outstanding performance (accuracy of 100%) using the five critical aroma. Moreover, the potential chemical basis of odors was sought through sensory evaluation. In addition, this study provides the theoretical and practical foundation for geographical origin traceability and quality evaluation.

Anthocyanins from Opuntia ficus-indica Modulate Gut Microbiota Composition and Improve Short-Chain Fatty Acid Production

Opuntia ficus-indica is rich in a variety of active substances, such as anthocyanins, flavonoids, and polysaccharides. Some studies have shown that anthocyanins extracted from natural plants can regulate intestinal flora. The fruit was used as raw material, and anthocyanins were extracted from it. In vivo experiments were used to study the effect of Opuntia ficus-indica anthocyanins on the mouse intestine by 16S rRNA high-throughput sequencing (NovaSeq 6000 platform) and gas chromatography (hydrogen flame ionization detector (FID)) methods. Microbiota and effects of short-chain fatty acids (SCFAs). The results showed that after feeding anthocyanins, the diversity of intestinal microorganisms in mice was significantly increased (p < 0.05), the ratio of Firmicutes/Bacteroidetes (F/B value) was significantly decreased (p < 0.05), the relative abundances of beneficial bacteria Lactobacillus, Bifidobacterium, Prevotella, and Akkermansia in the intestinal tract of mice were significantly increased (p < 0.05), and the relative abundance of pathogenic bacteria Escherichia-Shigella and Desulfovibrio decreased significantly (p < 0.05). Furthermore, anthocyanins significantly increased the content of short-chain fatty acids in the cecum of mice, among which the content of acetic acid, propionic acid, and butyric acid increased the most. Opuntia ficus-indica anthocyanins can change the microbial diversity and flora composition of the mouse gut and promote the production of short-chain fatty acids. The findings provide a theoretical basis for the use of Opuntia ficus-indica anthocyanins as dietary supplements to regulate human intestinal flora.

Anthocyanins from Pomegranate (Punica granatum L. ) and Their Role in Antioxidant Capacities in Vitro

As phytochemicals, anthocyanins are not only responsible for the diverse colors in nature, but are associated with broad-spectrum health-promoting effects for human beings. Pomegranate is abundant in anthocyanins which possess high antioxidant capacities. However, the pomegranate anthocyanins profile and their contributions to antioxidant capacities are not fully depicted. The purpose of this paper is to review anthocyanins from pomegranate as important antioxidants. Total anthocyanin content (TAC) and six major components vary greatly with intrinsic and extrinsic factors. In pomegranate, anthocyanins mainly acted as primary antioxidants, while their action as secondary antioxidants were not conclusive. The antioxidant potentials of anthocyanins were significantly affected by factors especially chemical structure and detection assays in vitro. The current knowledge may provide insights into potential applications for pomegranate anthocyanins based on their antioxidant activities.