Utilization of Lemon Peel for the Production of Vinegar by a Combination of Alcoholic and Acetic Fermentations

Lemon peel is the major by-product of lemon juice processing and is currently underutilized. In this study, we explored the feasibility of using lemon peel as a raw material for making vinegar. Lemon peel was homogenized, treated with pectinase (30,000 U/g, 0.1%) at 50 °C for 4 h, and then filtered. The obtained lemon peel juice was first subjected to alcoholic fermentation by Saccharomyces cerevisiae var. FX10, and then acetic fermentation by an acid tolerant Acetobacter malorum, OQY-1, which was isolated from the lemon peels. The juice yield of the lemon peel was 62.5%. The alcoholic fermentation yielded a lemon peel wine with an alcoholic content of 5.16%, and the acetic acid fermentation produced a vinegar with a total acid content of 5.04 g/100 mL. A total of 36 volatile compounds were identified from the lemon vinegar, with some compounds such as esters and some alcohols that increased significantly during alcoholic fermentation while alcohols, terpenoids, and some esters decreased significantly during the fermentations. E-nose and E-tongue analyses coupled with principal component and discriminant factor analyses (PCA and DFA) were able to discriminate the samples at different fermentation stages. Overall, this work demonstrates the potential to transform lemon peel into a valuable product, thus reducing the waste of lemon processing and adding value to the industry.

Marination with aronia, grape and hawthorn vinegars affects the technological, textural, microstructural and sensory properties of spent chicken meat

1. The purpose of the present research was to detect the efficacies of various vinegars (aronia, grape and hawthorn) used as marination solutions on the physicochemical, technological, textural and sensory properties of spent chicken meat. The pH, colour parameters, cooking loss, marinade absorption, yield, texture (TPA and MORS), characteristics via scanning electron microscopy (SEM) and sensory properties of marinated spent chicken samples were determined.2. Marination solutions used in the treatment groups were prepared with aronia, grape and hawthorn vinegars. The samples were agitated by hand to provide even dispersion of the solid ingredients in the marinades and were kept at 4°C for 24 h.3. The pH values of the samples were between 4.70 and 6.04. Marination with various marination solutions caused significant differences in terms of the a* and b* values of samples (P < 0.05). While marination with aronia vinegar decreased the b value of the samples, the use of grape and hawthorn vinegars in the marination solutions increased this value.4. Hardness and chewiness were the lowest in samples marinated with grape vinegar (P < 0.05) and were 135.14 and 48.79 N, respectively. As a result of marination with various vinegars, there was a significant (P < 0.05) decrease in the MORSF and MORSE values.5. Marinade absorption values decreased by marination with various vinegars. The highest yield values were found in the samples marinated with hawthorn vinegar (P < 0.05). The SEM indicated that marination with aronia, grape and hawthorn vinegar caused larger gaps between muscle fibres compared to the control samples.6. Samples marinated with vinegars had higher texture scores compared with the control. Consequently, the marination with vinegars such as aronia, grape and hawthorn has the potential to improve the technical and textural properties of spent chicken meat.

Drying Kinetic of Jaboticaba Berries and Natural Fermentation for Anthocyanin-Rich Fruit Vinegar

This study aimed to determine the drying kinetic of jaboticaba berries that were then used for the fermentation of natural fruit vinegar. The drying behavior was fitted well to the thin-layer kinetic model of Midilli et al. in a vacuum oven at 40 °C. Moisture diffusion was the dominant mechanism because two falling rate periods were observed. The effective moisture diffusivity was decreased (2.52 × 10−10 m2/s) after being pretreated with 70% sugar (1.84 × 10−10 m2/s) and 10% salt (6.73 × 10−11 m2/s) solutions. Fresh berry vinegar was found to have higher flavonoids, including anthocyanins, to exhibit higher antiradical and anti-pathogenic microorganism activities. However, the phenolic content in dried berries vinegar was higher, mainly from the bond breaking of tannins and lignins from fruit peel. Some extent of oxidation occurred because of the change in the color index of vinegar samples. The acidity of both vinegars was 3% acetic acid. Headspace GC-MS also detected acetic acid as the major compound (>60%) in the vapor of vinegar samples. A wide range of non-volatile compounds composed of alkaloids, terpenoids, flavonoids, organic acids, and sugar derivatives was detected by UHPLC-TWIMS-QTOFMS. The peak intensity of anthocyanins was reduced by 28−77% in dried berry vinegar. Therefore, it is better to prepare natural fruit vinegar using fresh berries, preserving anthocyanins for high antioxidant capacity.

Sensorial, antioxidant and antimicrobial evaluation of vinegars from surpluses of physalis (Physalis pubescens L.) and red pitahaya (Hylocereus monacanthus)

BACKGROUND

To reduce postharvest losses, substandard fruit and agricultural surpluses can productively be used as raw material for vinegar production. The present study aimed to prepare vinegars from surpluses of physalis (Physalis pubescens L.) and red pitahaya (Hylocereus monacanthus) and then evaluate their sensorial characteristics, antimicrobial activities, total phenolic content (TPC) and total antioxidant capacity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzo thiazoline-6-sulfonic acid) methods.

RESULTS

Two vinegars were produced by submerged fermentation using physalis and red pitahaya fruits surpluses. Physalis and red pitahaya vinegars had 47 and 45 g L^-1 acetic acid, respectively, and both vinegars contained approximately 1 g L^-1 ethanol. Both vinegars displayed antimicrobial activity against Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella enteritidis. The TPC of physalis and red pitahaya vinegar was 0.5638 and 0.3656 g L^-1 g gallic acid L^-1 for physalis and red pitahaya, respectively. A similar antioxidant activity was detected in both the wines and vinegars. The sensorial analysis revealed that the consumers 'like moderately' each vinegar, and citric aroma was noted in the physalis vinegar.

CONCLUSION

In the present study, vinegars with sensorial characteristics approved by consumers were developed using fruit surpluses, adding value through a new product making use of a simple methodology that is both inexpensive and demonstrates a good yield. © 2018 Society of Chemical Industry.

Antioxidant Activities, Phenolic Profiles, and Organic Acid Contents of Fruit Vinegars

Fruit vinegars are popular condiments worldwide. Antioxidants and organic acids are two important components of the flavors and health benefits of fruit vinegars. This study aimed to test the antioxidant activities, phenolic profiles, and organic acid contents of 23 fruit vinegars. The results found that the 23 fruit vinegars varied in ferric-reducing antioxidant power (FRAP, 0.15⁻23.52 μmol Fe(II)/mL), Trolox equivalent antioxidant capacity (TEAC, 0.03⁻7.30 μmol Trolox/mL), total phenolic content (TPC, 29.64⁻3216.60 mg gallic acid equivalent/L), and total flavonoid content (TFC, 2.22⁻753.19 mg quercetin equivalent/L) values. Among the 23 fruit vinegars, the highest antioxidant activities were found in balsamic vinegar from Modena (Galletti), Aceto Balsamico di Modena (Monari Federzoni), red wine vinegar (Kühne), and red wine vinegar (Galletti). In addition, polyphenols and organic acids might be responsible for the antioxidant activities of fruit vinegars. The most widely detected phenolic compounds in fruit vinegars were gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, and p-coumaric acid, with tartaric acid, malic acid, lactic acid, citric acid, and succinic acid the most widely distributed organic acids. Overall, fruit vinegars are rich in polyphenols and organic acids and can be a good dietary source of antioxidants.

Effects of a vinegar-based multi-micronutrient supplement in rats: a multi-pronged assessment of dietary impact

We determined the effects of continuous access to drinking of water with a vinegar-based multi-micronutrient (VMm) supplement containing rice and fruit vinegars, vitamins, organic acids and sugars during gestation, lactation, and early adulthood in rats. Pregnant rats were provided with reverse-osmosis water or VMm water from the start of pregnancy through the time of weaning. Weaned pups consumed the same drinking water for 3-12 additional weeks. We examined fecal metabolite and microbial profiles, and other physiological parameters. Body weights were less in rats that drank VMm water. Thirty fecal metabolites involved in amino acid and dipeptide metabolism were significantly altered in VMm-supplemented rats. Analysis of microbial 16S rRNA showed enrichment of bacteria in the family S24-7 in VMm-supplemented rats, and one in Ruminococcaceae in controls. Our data show that a VMm-containing beverage can alter growth, and gut metabolism and microbial community. Future work to correlate these parameters is warranted.

Vinegar Production from Jabuticaba (Myrciaria jaboticaba) Fruit Using Immobilized Acetic Acid Bacteria

Cell immobilization comprises the retention of metabolically active cells inside a polymeric matrix. In this study, the production of jabuticaba (Myrciaria jaboticaba) vinegar using immobilized Acetobacter aceti and Gluconobacter oxydans cells is proposed as a new method to prevent losses of jabuticaba fruit surplus. The pulp of jabuticaba was processed and Saccharomyces cerevisiae CCMA 0200 was used to ferment the must for jabuticaba wine production. Sugars, alcohols (ethanol and glycerol) and organic acids were assayed by high-performance liquid chromatography. Volatile compounds were determined by gas chromatography-flame ionization detector. The ethanol content of the produced jabuticaba wine was approx. 74.8 g/L (9.5% by volume) after 168 h of fermentation. Acetic acid fermentation for vinegar production was performed using a mixed culture of immobilized A. aceti CCT 0190 and G. oxydans CCMA 0350 cells. The acetic acid yield was 74.4% and productivity was 0.29 g/(L·h). The vinegar had particularly high concentrations of citric (6.67 g/L), malic (7.02 g/L) and succinic (5.60 g/L) acids. These organic acids give a suitable taste and flavour to the vinegar. Seventeen compounds (aldehydes, higher alcohols, terpene, acetate, diether, furans, acids, ketones and ethyl esters) were identified in the jabuticaba vinegar. In conclusion, vinegar was successfully produced from jabuticaba fruits using yeast and immobilized mixed cultures of A. aceti and G. oxydans. To the best of our knowledge, this is the first study to use mixed culture of immobilized cells for the production of jabuticaba vinegar.