Impact of the Ripening Stage of Wax Apples on Chemical Profiles of Juice and Cider

Nutritional, Bioactive, and Volatile Characteristics of Two Types of Sorbus domestica Undervalued Fruit from Northeast of Iberian Peninsula, Spain

The promotion of food from underutilized plants can help combat biodiversity loss, foster cultural preservation, and empower farmers in the face of market pressures and sustainable production conditions. The nutritional and aromatic characterization of two undervalued types of Sorbus domestica fruits, differentiated by their apple and pear shapes, has been carried out. Official Association of Analytical Communities methods have been used for proximate composition and mineral analysis determinations, and gas chromatography was used for the analysis of volatile components in three states of ripeness and compared with the aromas of fresh apple and quince jam. S. domestica fruits are a good source of K, Ca, Fe, and fiber and are an important source of antioxidants in the human diet. S. domestica fruits have proven to be very distinctive in the aromatic fraction. 1-hexanol, hexyl 1,3-octanediol, phenylacetaldehyde, nonanal, hexanal, and α-farnesene are the most potent odor compounds in the overripening stage of the fruits. The aroma profiles of immature S. domestica fruits were dominated by aldehydes, while in the overripe stage, the fruit accumulated abundant esters, alcohols, and sesquiterpenoids. S. domestica fruits could be introduced as an alternative to seasonal fruit consumption and could generate sustainable production and consumption alternatives while recovering cultural and food heritage.

Contribution of amino acids to Alicyclobacillus acidoterrestris DSM 3922T resistance towards acid stress

Spoilage of juice and beverages by a thermo-acidophilic bacterium, Alicyclobacillus acidoterrestris, has been considered to be a major and widespread concern for juice industry. Acid-resistant property of A. acidoterrestris supports its survival and multiplication in acidic juice and challenges the development of corresponding control measures. In this study, intracellular amino acid differences caused by acid stress (pH 3.0, 1 h) were determined by targeted metabolomics. The effect of exogenous amino acids on acid resistance of A. acidoterrestris and the related mechanisms were also investigated. The results showed that acid stress affected the amino acid metabolism of A. acidoterrestris, and the selected glutamate, arginine, and lysine contributed to its survival under acid stress. Exogenous glutamate, arginine, and lysine significantly increased the intracellular pH and ATP level, alleviated cell membrane damage, reduced surface roughness, and suppressed deformation caused by acid stress. Additionally, the up-regulated gadA and speA genes and the enhanced enzymatic activity confirmed that glutamate and arginine decarboxylase systems played a crucial role in maintaining pH homeostasis of A. acidoterrestris under acid stress. Our research reveals an important factor contributing to acid resistance of A. acidoterrestris, which provides an alternative target for effectively controlling this contaminant in fruit juices.

Watery Rose Apple: A Comprehensive Review of Its Traditional Uses, Nutritional Value, Phytochemistry, and Therapeutic Merits against Inflammation-Related Disorders

The myrtle family, Myrtaceae, constitutes over 5500 species, and Syzygium is considered the largest genus of the flowering plants within the family. The watery rose apple, Syzygium aqueum, is a traditional medicinal plant with various bioactive compounds distributed in all plant parts. These include phenolic compounds, flavonoids, tannins, terpenoids, and essential oils. S. aqueum extracts and their isolated compounds showed multiple beneficial biological effects such as antibacterial, antifungal, antidiabetic, analgesic, antimalarial, antioxidant, anti-inflammatory, and anticancer activities. This review is aimed at discussing all the available information about the nutritional value, traditional uses, and therapeutic properties of the leaves, fruit, and stem bark of the plant, in addition to the distribution of phytoconstituents in its different parts as well as recommend future research directions on this species to promote its clinical uses.

Characterization of volatile aroma compounds in litchi (Heiye) wine and distilled spirit

This study used litchi (Heiye) wine and distilled spirit as raw experimental materials to analyze the volatile aroma compounds. Qualitative and quantitative determination of aromatic components was studied using stir bar sportive extraction (SBSE) and gas chromatography coupled to mass spectrometry (GC/MS). Results indicated that a total of 128 different types of aroma compounds were observed, which belonged to six chemical groups, including 39 esters, 16 alcohols, 16 acids, 22 terpenes, 17 aldehydes and ketones, and 18 other compounds. In particular, esters were the highest among all six categories and represented approximately 52% of the total flavor component content in litchi distilled spirit. The odor activity values (OAVs) revealed 22 types of aroma compounds with OAVs >1 in this test. It is possible that the produced litchi distilled spirit had a stronger varietal character due to the increased concentrations and OAVs of β-damascenone, linalool, ethyl butyrate, ethyl isovalerate, ethyl caproate, trans-rose oxide, and cis-rose oxide. Taking the OAVs into account, we evaluated the characteristic aromas for litchi wine and litchi distilled spirit.

Strategies to Improve the Potential Functionality of Fruit-Based Fermented Beverages

It is only recently that fermentation has been facing a dynamic revival in the food industry. Fermented fruit-based beverages are among the most ancient products consumed worldwide, while in recent years special research attention has been granted to assess their functionality. This review highlights the functional potential of alcoholic and non-alcoholic fermented fruit beverages in terms of chemical and nutritional profiles that impact on human health, considering the natural occurrence and enrichment of fermented fruit-based beverages in phenolic compounds, vitamins and minerals, and pro/prebiotics. The health benefits of fruit-based beverages that resulted from lactic, acetic, alcoholic, or symbiotic fermentation and specific daily recommended doses of each claimed bioactive compound were also highlighted. The latest trends on pre-fermentative methods used to optimize the extraction of bioactive compounds (maceration, decoction, and extraction assisted by supercritical fluids, microwave, ultrasound, pulsed electric fields, high pressure homogenization, or enzymes) are critically assessed. As such, optimized fermentation processes and post-fermentative operations, reviewed in an industrial scale-up, can prolong the shelf life and the quality of fermented fruit beverages.

Impact of germination on the chemical profile of HomChaiya rice wort and beer

HomChaiya rice is one of the important rice varieties in Thailand. However, the commercial value of this rice is very limited as it is not widely known and has limited availability. The present research aimed to produce an alcoholic beverage from malted HomChaiya rice, and various chemical profiles (physicochemical, phytochemicals, volatiles, and amino acids) were studied. HomChaiya rice was germinated for different periods (3, 5, and 7 days), kilned at 60 °C, and used to produce wort and beer. Physicochemical qualities such as pH, brix, titratable acidity, viscosity, soluble nitrogen, FAN, and extractability were higher in the wort, and the results were significantly influenced by the germination time. On the other hand, the color values were higher in the beer samples, and prolonged germination brightened the beer color. The total phenolic content, flavonoid content, and various antioxidant potentials (DPPH, ABTS, and reducing power) were significantly increased in the beer samples when made with rice malt germinated for 7 days compared to the wort under similar conditions. Wort samples had 13 identified volatiles, whereas the beer samples had 30 volatile compounds. Furthermore, 20 amino acids were identified, and most of them were found at a higher level in the wort samples compared to beer samples, and prolonged germination slightly increased the amino acid levels. The beer samples' sensory characteristics showed that the HomChaiya rice germination period had no significant effect.

An alcoholic beverage from malted HomChaiya rice was produced and various chemical profiles and sensory characteristics were studied.

The Effect of Pasteurization and Shelf Life on the Physicochemical, Microbiological, Antioxidant, and Sensory Properties of Rose Apple Cider during Cold Storage

Rose apple fruits (Syzygium agueum Alston cv. Taaptimjan) were used to produce cider to overcome their limitation of short shelf life. Following fermentation, alternative pasteurization conditions at 63 °C for 15 s and at 71 °C for 6 s were compared. The effects of pasteurization conditions on physicochemical properties, microbial safety, antioxidant capacity, and sensory properties of the cider were investigated during storage for 6 months at refrigerated temperature. The unpasteurized cider had 5.9% ethanol content with TSS of 4.1 °Brix. Alcohol content of this treatment group increased while TSS decreased during storage, as effects of continuing fermentation. Pasteurization at 63 or 71 °C effectively prolonged cider shelf life to 3 and 6 months, respectively. Nonetheless, the processing significantly decreased contents of ascorbic acid and antioxidants and affected sensory profile of the cider. Principal component analysis (PCA) indicated storage time as the dominant factor determining cider quality. Trained panelists in the sensory study perceived more intense sweetness, less sourness, and less flavor in the pasteurized samples compared to the control group. The pasteurization conditions 71 °C for 6 s achieved microbiological safety and resulted in desirable sensory quality for up to 6 months of shelf life.

<i>Syzygium samarangense</i> Volatile Oil Inhibited Bacteria Growth and Extracellular Protease of <i>Salmonella typhimurium</i>

BACKGROUND AND OBJECTIVE

Medicinal plants are fast becoming essential pharmaceuticals for disease and infection management. The vast antimicrobial properties of these plants reside in the inhibitory properties of their endogenous secondary metabolites. Therefore, this study aimed to assess if the volatile oil of Syzygium samarangense inhibits enteric bacteria growth and its effect against the caseinolytic activity of the extracellular protease of Salmonella typhimurium.

MATERIALS AND METHODS

The volatile oil was extracted by hydrodistillation, while the antimicrobial assay was assessed with the microdilution method. The extracellular protease was partially purified by salting out, followed by size-exclusion chromatography. The mode of inhibition of this enzyme was deduced from the enzyme-substrate kinetics using a line-weaver burke plot.

RESULTS

The antimicrobial properties of the oil were reported against ten enteric bacteria. Proteus vulgaris has the highest IC50 value of 0.75±0.004% v/v, while S. typhimurium, the most sensitive bacterium, showed the lowest IC50 value of 0.17±0.005% v/v. The extracellular protease of S. typhimurium was partially purified to achieve 3.73 purification fold and 314.2 μmol min-1 mg-1 protein. The optimal caseinolytic activity of this enzyme was found at pH 7.5 and 40 °C. The protease showed significantly higher activity in the presence of Zn2+ (9.3±0.33 U min-1) as compared to the control (7.0±0.58 U min-1) (p<0.05), however, K+, Ca2+, Co2+, Ba2+, Pb2+ and Hg2+ considerably reduced the enzyme activity. The activity of this enzyme was competitively inhibited by the volatile oil as an inhibitor.

CONCLUSION

The volatile oil of S. samarangense inhibited a wide range of enteric bacteria and, therefore proposed as a potential antimicrobial agent. Inhibiting the extracellular protease of S. typhimurium may be one of its modes of action against these pathogens.

Evaluation of the volatile profile of wax apple (Syzygium samarangense) wines fermented with different commercial Saccharomyces cerevisiae strains

The effect of four commercial Saccharomyces cerevisiae strains (D254, VIC, BV818, and RV100) on the volatile profile of wax apple (Syzygium samarangense) wine was investigated in this study. Alcohols and esters were the most two abundant groups of identified volatiles in wax apple wines. However, different S. cerevisiae strains possess various capacities in releasing/synthesizing volatiles with varied mRNA levels of genes involved in volatiles metabolism during wax apple wine fermentation. VIC, which yielded the highest total concentration of volatiles and largest number of volatiles with odor activity value (OAV) > 1, could be used as a starter culture to produce wax apple wine characterized with intense aroma. D254 and RV100, which produced the greatest variety of volatiles and scored the highest in global aroma, respectively, could be used to enhance the wine complexity. Four wax apple wines could be differentiated by their main volatile compounds.

Phenolic composition of apple products and by-products based on cold pressing technology

Cold pressing technology is a new technology using during the apple juice processing, which involved peeling and deseeding of apples at low temperature. The phenolics of apple juice, apple vinegar and apple pomace generated by cold pressing and traditional process were investigated. The results showed that the total phenols and flavanols of cold pressing apple juice were lower than those of traditional process. The total phenols content of peel pomace extract was significantly higher than that of the pulp pomace by almost tenfold, which showed that the peels and seeds were valuable sources of phenolic compounds. The total phenols of apple vinegars were significantly different. The predominant compounds in apple products were phloridzin and chlorogenic acid, while the apple pomaces based on cold pressing technology had significantly high content of phenolic compounds, indicating that the cold pressing technology could facilitated the use of apple pomace for bioactive compounds.