Nisin production in acid whey with Lactococcus strains

Author(s):  
Diana Paveljšek
Keyword(s):  
Author(s):  
Prof. Asoc. Dr. Shurki MAXHUNI ◽  
Prof.Asiss.Dr.Nerimane BAJRAKTARI

The dairy industry seems to have convinced the food industry that whey is a miracle product. The list of supposed benefits it gives to food is as long as your arm. Some of the benefits may be real. Whey is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. To produce cheese, rennet or an edible acid is added to heated milk. This makes the milk coagulate or curdle, separating the milk solids (curds) from the liquid whey. Sweet whey is the byproduct of rennet-coagulated cheese and acid whey (also called sour whey) is the byproduct of acid-coagulated cheese. Sweet whey has a pH greater than or equal to 5.6, acid whey has a pH less than or equal to 5.1. Whey is also a great way to add sweetness to a product without having to list sugar as an ingredient as whey contains up to 75% lactose. And it sounds healthy. This study is done to research the examinations for the production of mozzarella cheese from Cow’s milk, after research and analyses of a physical-chemical peculiar feature of whey from coagulum. We have followed the processes from the drying of whey from the coagulum analyzer's physical-chemical peculiar feature. We carried out three experiments. For every experiment, we took three patterns and analyzed the physical-chemical. The calculation was appraised statistically. This paper deals with the research of% of whey fat during the process of milk production from standardized to non-standardized milk. Where% of whey fat should be an economic indicator for standardizing milk for dairy production.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 898
Author(s):  
Hebatoallah Hassan ◽  
Daniel St-Gelais ◽  
Ahmed Gomaa ◽  
Ismail Fliss

Clostridium tyrobutyricum spores survive milk pasteurization and cause late blowing of cheeses and significant economic loss. The effectiveness of nisin-producing Lactococcus lactis ssp. lactis 32 as a protective strain for control the C. tyrobutyricum growth in Cheddar cheese slurry was compared to that of encapsulated nisin-A. The encapsulated nisin was more effective, with 1.0 log10 reductions of viable spores after one week at 30 °C and 4 °C. Spores were not detected for three weeks at 4 °C in cheese slurry made with 1.3% salt, or during week 2 with 2% salt. Gas production was observed after one week at 30 °C only in the control slurry made with 1.3% salt. In slurry made with the protective strain, the reduction in C. tyrobutyricum count was 0.6 log10 in the second week at 4 °C with both salt concentration. At 4 °C, nisin production started in week 2 and reached 97 µg/g after four weeks. Metabarcoding analysis targeting the sequencing of 16S rRNA revealed that the genus Lactococcus dominated for four weeks at 4 °C. In cheese slurry made with 2% salt, the relative abundance of the genus Clostridium decreased significantly in the presence of nisin or the protective strain. The results indicated that both strategies are able to control the growth of Clostridium development in Cheddar cheese slurries.


LWT ◽  
2021 ◽  
Vol 142 ◽  
pp. 111093
Author(s):  
Wei Liu ◽  
Jingping Zhou ◽  
Fangdai Tan ◽  
Hao Yin ◽  
Chunyan Yang ◽  
...  

2021 ◽  
Vol 9 (1) ◽  
pp. 100
Author(s):  
Alba C. Mayta-Apaza ◽  
Israel García-Cano ◽  
Konrad Dabrowski ◽  
Rafael Jiménez-Flores

The disposal of acid whey (Aw), a by-product from fermented products, is a problem for the dairy industry. The fishery industry faces a similar dilemma, disposing of nearly 50% of fish processed for human consumption. Economically feasible and science-based alternatives are needed to overcome this problem. One possible solution is to add value to the remaining nutrients from these by-products. This study focuses on the breakdown of nutrients in controlled fermentations of Aw, fish waste (F), molasses (M), and a lactic acid bacteria (LAB) strain (Lr). The aim was to assess the dynamic variations in microbial diversity and the biochemical changes that occur during fermentation. Four treatments were compared (AwF, AwFM, AwFLr, and AwFMLr), and the fermentation lasted 14 days at 22.5 °C. Samples were taken every other day. Colorimetric tests for peptide concentrations, pH, and microbial ecology by 16S-v4 rRNA amplicon using Illumina MiSeq were conducted. The results of the microbial ecology showed elevated levels of alpha and beta diversity in the samples at day zero. By day 2 of fermentation, pH dropped, and the availability of a different set of nutrients was reflected in the microbial diversity. The fermentation started to stabilize and was driven by the Firmicutes phylum, which dominated the microbial community by day 14. Moreover, there was a significant increase (3.6 times) in peptides when comparing day 0 with day 14, making this treatment practical and feasible for protein hydrolysis. This study valorizes two nutrient-dense by-products and provides an alternative to the current handling of these materials.


2021 ◽  
pp. 105163
Author(s):  
Ana G. Ortiz Quezada ◽  
Alejandra Castilla Asaf ◽  
Gavin L. Sacks
Keyword(s):  

1976 ◽  
Vol 43 (1) ◽  
pp. 45-51 ◽  
Author(s):  
P. J. Argyle ◽  
N. Jones ◽  
R. C. Chandan ◽  
J. F. Gordon

SummarySlow, irreversible aggregation of whey proteins in acidified milk or whey at pH 3·4–4·6 held for up to 10 d at 35–45°C was revealed by the reduction of discrete bands in disc electrophoresis. The aggregation was confirmed by precipitation of protein observed in stored, acid whey. The rate of aggregation of all protein fractions increased with the acidity and the storage temperature. It was enhanced by the presence of casein, but was unaffected by the presence of milk fat or by pasteurization of the fresh, unacidified milk at 70°C. The effect may contribute to the physical properties of certain fresh cheeses and other cultured dairy products.


Sign in / Sign up

Export Citation Format

Share Document