Impact of lactic acid fermentation on acids, sugars, and phenolic compounds in black chokeberry and sea buckthorn juices.

The aim of this research was to study the potential of malolactic fermentation to modify the composition of the juices of sea buckthorn, chokeberry and lingonberry. Juices were prepared with and without pectinolytic enzyme treatment, followed by fermentation with commercially available strains of Lactobacillus plantarum, originally isolated from fermented plant materials. The juices before and after the fermentation were analyzed with GC-FID, HPLC-DAD, and HPLC-MS. Enzyme treatment significantly increased the phenolic content in the juices by 11-50%. None of strains showed ability to ferment lingonberry juice. On the other hand, L. plantarum DSM 10492 and DSM 20174 converted all malic acid to lactic acid in sea buckthorn and chokeberry juices, respectively. Fermentation with DSM 10492 reduced the content of flavonols by 9-14% and hydroxycinnamic acids by 20-24% in chokeberry juice. Flavonol glycosides and sugars in sea buckthorn as well as anthocyanins in chokeberry remained unaffected by the fermentation.

Markkinen N ，Laaksonen O ，Nahku R ，Kuldjärv R ，Yang B ... -  《-》

Dynamics of changes in organic acids, sugars and phenolic compounds and antioxidant activity of sea buckthorn and sea buckthorn-apple juices during malolactic fermentation.

Sea buckthorn (Hippophaë rhamnoides L.) berries have high biological value as a rich source of phenolic compounds, fatty acids and vitamins A, C, E. Due to the high organic acid content and sour taste, the fruits are rarely used in juice production. Therefore, the study aimed to determine the metabolic activity of Lactobacillus plantarum, Lactobacillus plantarum subsp. argentoratensis and Oenococcus oeni strains along with the dynamics of changes in organic acids, sugars, phenolic compounds, and antioxidant activity during 72-h fermentation of 100% sea buckthorn and mixed with apple (1:1) juices. The strongest malolactic conversion was in mixed juices (to 75.0%). The most efficient strains were L. plantarum DSM 10492, 20174 and 6872. L. plantarum strains caused an increase in flavonols and antioxidant activity of sea buckthorn-apple juices. The results can be used to select conditions and strains in industrial-scale fermentation, to produce novel sea buckthorn products and increase their consumption.

Tkacz K ，Chmielewska J ，Turkiewicz IP ，Nowicka P ，Wojdyło A ... -  《-》

Influence of lactic acid fermentation on the phenolic profile, antioxidant activities, and volatile compounds of black chokeberry (Aronia melanocarpa) juice.

Wang J ，Wei B ，Xu J ，Jiang H ，Xu Y ，Wang C ... -  《-》

Effects of cholesterol-lowering probiotic fermentation on the active components and in vitro hypolipidemic activity of sea buckthorn juice.

Sea buckthorn has lipid-lowering properties and is widely used in the development of functional foods. In this study, a probiotic (Lactobacillus plantarum, Lp10211) with cholesterol-lowering potential and acid and bile salt resistant was screened for the fermentation of sea buckthorn juice. Changes in the active ingredients, such as sugars and phenolics, before and after fermentation, as well as their in vitro lipid-lowering activities, were compared. The contents of reducing and total sugars decreased substantially after fermentation. Lp10211 primarily utilized fructose for growth and reproduction, with a utilization rate of 76.9%. The phenolic compound content of sea buckthorn juice increased by 37.06% after fermentation and protected the phenolic components from degradation (protocatechuic and p-coumaric acids) and produced new polyphenol (shikimic acid). Enhanced inhibition of pancreatic lipase activity (95.42%) and cholesterol micellar solubility (59.15%) was evident. The antioxidant properties of the fermentation broth were improved. Notably, Lp10211 preserved the color and reversed browning in sea buckthorn juice. The collective findings indicate that fermentation of sea buckthorn juice by Lp10211 may enhance the functional components and lipid-lowering activity of sea buckthorn, which may provide a new approach for the development of lipid-lowering foods.

Fan Y ，Shang Y ，Li F ，Liu J ，Wang D ，Zhang Y ，Yu X ，Wang W ... -  《-》

NMR-based metabolomics approach on optimization of malolactic fermentation of sea buckthorn juice with Lactiplantibacillus plantarum.

This work investigated the impact of malolactic fermentation on the metabolomic profile of sea buckthorn juice to optimize the fermentation process for flavor modification. Six strains of L. plantarum were used with varied pH of the juice, cell acclimation, and fermentation time. 1H-NOESY spectra were acquired from fresh and fermented juices with a total of 46 metabolites identified. Less sugars and quinic acid were metabolized at pH 2.7 while oxidation of ascorbic acid was reduced at pH 3.5. l-Malic acid, essential amino acids, and nucleosides were consumed early during fermentation while sugars in general were consumed later in the fermentation. If deacidification is the main target of fermentation, strains that produce less acids and ferment less sugars, shorter fermentation time, and lower starter pH should be used. Higher starter pH and longer fermentation time promote formation of antimicrobial compounds and potentially increase antioxidant stability.

Markkinen N ，Pariyani R ，Jokioja J ，Kortesniemi M ，Laaksonen O ，Yang B ... -  《-》