scholarly journals The effects of vegetable pickling conditions on the dynamics of microbiota and metabolites

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11123
Author(s):  
Kazunori Sawada ◽  
Hitoshi Koyano ◽  
Nozomi Yamamoto ◽  
Takuji Yamada

Background Salting is a traditional procedure for producing pickled vegetables. Salting can be used as a pretreatment, for safe lactic acid fermentation and for salt stock preparation. This study aimed to provide valuable knowledge to improve pickle production by investigating the dynamics of microbiota and metabolites during the pretreatment and salt stock preparation processes, which have previously been overlooked. The differences in these process conditions would be expected to change the microbiota and consequently influence the content of metabolites in pickles. Methods Samples, collected from eight commercial pickle manufacturers in Japan, consisted of the initial raw materials, pickled vegetables and used brine. The microbiota were analyzed by 16S rRNA sequencing and the metabolites quantified by liquid chromatograph-mass spectrometry. Statistical analyses helped to identify any significant differences between samples from the initial raw materials, pretreatment process and salt stock preparation process groups. Results Under pretreatment conditions, aerobic and facultative anaerobic bacteria were predominant, including Vibrio, a potentially undesirable genus for pickle production. Under salt stock preparation conditions, the presence of halophilic bacteria, Halanaerobium, suggested their involvement in the increase in pyruvate derivatives such as branched-chain amino acids (BCAA). PICRUSt analysis indicated that the enhanced production of BCAA in salt stock was caused not by quantitative but by qualitative differences in the biosynthetic pathway of BCAA in the microbiota. Conclusion The differences in the microbiota between pretreatment and previously studied lactic acid fermentation processes emphasized the importance of anaerobic conditions and low pH under moderate salinity conditions for assuring safe pickle production. The results from the salt stock preparation process suggested that the Halanaerobium present may provide a key enzyme in the BCAA biosynthetic pathway which prefers NADH as a coenzyme. This feature can enhance BCAA production under anaerobic conditions where NADH is in excess. The effects shown in this study will be important for adjusting pickling conditions by changing the abundance of bacteria to improve the quality of pickled vegetables.

Author(s):  
Benard O. Oloo ◽  
A. A. Shitandi ◽  
S. Mahungu ◽  
J. B. Malinga ◽  
Rose B. Ogata

This study aimed to establish the effects of lactic fermentation on the levels of β-carotene in selected  orange fleshed sweet potato (OFSP) varieties from Kenya.  Furthermore,it sought to demonstrate fermentation as a potential process for making new products from sweet potato with enhanced nutraceutical attributes. The varieties (Zapallo, Nyathiodiewo and SPK004/06) were fermented with Lactobacillus plantarum MTCC 1407 at 25 ± 2°C for 48 h and kept for 28 days to make lacto-pickles. During fermentation both analytical [pH, titratable acidity (TA), lactic acid (LA), starch, total sugar, reducing sugar (g/kg roots), texture (N/m2), β-carotene (mg/kg roots)] and sensory (texture, taste, flavour and after taste) attributes of sweet potato lacto-juice were evaluated. Process conditions were optimized by varying brine levels, with fermentation time. A UV-visible spectrophotometer was used to identify and quantify β-carotene. Any significant variations (p < 0.05) in analytical attributes between the fermented and unfermented samples (pH, LA, TA and β-carotene concentration) of lacto-pickles, prepared from the potato roots, were assessed. The study reported a final composition of 156.49mg/kg, 0.53mg/kg, 0.3N/m2, 1.3g/kg, 5.86g/kg, 0.5g/kg and 5.86g/kg for β-carotene, Ascorbic acid, texture; Starch, total sugars, LA and TA respectively, and a pH of 3.27. The fermented products were subjected to flavour profiling by a panel. The product sensory scores were 1.5 to 2.5 on a 5 point hedonic scale, ranging from dislike slightly to like much. The products with brine levels at 4 and 6% were most preferred. The retention of β-carotene was 93.97%. This demonstrated lactic acid fermentation as a better method for processing OFSP as the main nutritional attributes are retained. The final product was resistant to spoilage microorganisms after 28 days of fermentation. Further preservation could be obtained by addition of sodium metabisulphite. In conclusion, Lactic acid fermentation using L. plantarum is a novel method of producing Lacto pickles from Zapallo OFSP, with 93.97% β-carotene retention and adequate shelf life.


Author(s):  
Magda Gabriela Bratu ◽  
Lavinia Buruleanu ◽  
Daniela Avram

The influence of the storage time of vegetables - raw materials, the influence of fermentation temperature and the influence of the glucose addition about the lactic acid fermentation unfolding has been studied. Fresh carrots and carrots stored five months were pressed to raw juice and heat-treated at 70 degrees C for 20 minutes in the aim of destroy the undesirable microorganisms. Carrot juices were inoculated with lactic acid bacteria isolated from epiphytic microbiota at the concentration of 4x105 UFC/ml and fermented in a thermostat for 96 hours. During the fermentation the following analytical parameters were established: reducing sugars, total acidity, pH, amino acids content, nitrites content, ascorbic acid content. During fermentation the pH of carrot juices decreases from 6,15 to 3,99, while the total acidity increases from 0,06 to 1,62% (as lactic acid). Less than 25% of the initial content of ascorbic acid rests in the juices after 96 hours of fermentation. The amino acids content of juices, expressed as g N2/100g, increase with a middle of 50% in 96 hours, due of the proteins decomposition. The pre-digestion of these compounds improve the nutritional quality of the lactofermented juices. We found that the glucose supplement hasn’t a significant influence about the lactic acid accumulation. Also, at the end of the period of study, we found that the substratum metabolization was difficult in the sample with 1% glucose initial added. The quality of the raw materials, especially concerning the sugars content and the total acidity at the beginning of the fermentation process is important because a rapidly increase of acidity minimizes the influence of spoilage bacteria. To proceed from the results of the sensory analysis and the results of the chemical analysis we recommend stopping the fermentation of these juices after 72 hours.


2014 ◽  
pp. 683-690 ◽  
Author(s):  
Timo J. Koch ◽  
Joachim Venus

Renewable feedstock gain increasing attention in a time of rising oil prices and uncertainty about security of supply. Often those alternative resources do have high prices and processing costs. Fermentation processes are still of major significance in biotechnological processes. Sourcing cheap raw materials is a task of agricultural businesses. Apart from feedstock costs, energy and nutrients show a great impact on process economics. This actual study explores the potential of sugar beet thick juice and raw juice to act in a bifunctional manner, either as substrate or nutrient. Key finding of this studies are that even in absence of additional nutrients with raw juice lactic acid yields of up to 51,5% compared to 13,5% with thick juice and 2,4% with crystalline sugar were obtained. Even with raw juice an enentoermic purity of l(+)-lactic acid >98% could be achieved. The analytical comparison shows that raw juice can provide significant share of amino acids of a typical yeast extract addition while crystalline sucrose shows no contribution.


2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Benard O. Oloo ◽  
A. A. Shitandi ◽  
S. Mahungu ◽  
J. B. Malinga ◽  
Rose B. Ogata

This study aimed to establish the effects of lactic fermentation on the levels of β-carotene in selected  orange fleshed sweet potato (OFSP) varieties from Kenya.  Furthermore,it sought to demonstrate fermentation as a potential process for making new products from sweet potato with enhanced nutraceutical attributes. The varieties (Zapallo, Nyathiodiewo and SPK004/06) were fermented with Lactobacillus plantarum MTCC 1407 at 25 ± 2°C for 48 h and kept for 28 days to make lacto-pickles. During fermentation both analytical [pH, titratable acidity (TA), lactic acid (LA), starch, total sugar, reducing sugar (g/kg roots), texture (N/m2), β-carotene (mg/kg roots)] and sensory (texture, taste, flavour and after taste) attributes of sweet potato lacto-juice were evaluated. Process conditions were optimized by varying brine levels, with fermentation time. A UV-visible spectrophotometer was used to identify and quantify β-carotene. Any significant variations (p < 0.05) in analytical attributes between the fermented and unfermented samples (pH, LA, TA and β-carotene concentration) of lacto-pickles, prepared from the potato roots, were assessed. The study reported a final composition of 156.49mg/kg, 0.53mg/kg, 0.3N/m2, 1.3g/kg, 5.86g/kg, 0.5g/kg and 5.86g/kg for β-carotene, Ascorbic acid, texture; Starch, total sugars, LA and TA respectively, and a pH of 3.27. The fermented products were subjected to flavour profiling by a panel. The product sensory scores were 1.5 to 2.5 on a 5 point hedonic scale, ranging from dislike slightly to like much. The products with brine levels at 4 and 6% were most preferred. The retention of β-carotene was 93.97%. This demonstrated lactic acid fermentation as a better method for processing OFSP as the main nutritional attributes are retained. The final product was resistant to spoilage microorganisms after 28 days of fermentation. Further preservation could be obtained by addition of sodium metabisulphite. In conclusion, Lactic acid fermentation using L. plantarum is a novel method of producing Lacto pickles from Zapallo OFSP, with 93.97% β-carotene retention and adequate shelf life.


2017 ◽  
Vol 124 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Miloš Radosavljević ◽  
Jelena Pejin ◽  
Sunčica Kocić-Tanackov ◽  
Dragana Mladenović ◽  
Aleksandra Djukić-Vuković ◽  
...  

2018 ◽  
Vol 95 (2) ◽  
pp. 339-347 ◽  
Author(s):  
Miloš Radosavljević ◽  
Jelena Pejin ◽  
Milana Pribić ◽  
Sunčica Kocić‐Tanackov ◽  
Dragana Mladenović ◽  
...  

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
P Lorenz ◽  
S Duckstein ◽  
J Bertrams ◽  
U Meyer ◽  
F Stintzing

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