Fermentations as tools for making traditional and innovative foods and beverages

Fructophilic LAB and Digestibility

[FLAB]. If they're in medium with fructose and glucose they prefer using fructose. The main source for this specific group is fruit (but also honey, gastrointestinal tract of bees and flowers). They originated from habitats which have a very high concentration of fructose. Fructobacillus fructosus uses fructose but also mannitol. Enzymes hydrolyse fructans into fructose. FLAB using fructose and synthesising mannitol (is a polyol), other species that can use mannitol as source of energy. Total degradation of FOMDAPs during bread baking. You can get a bread without FODMAPs. Fructophilic LAB are suitable candidates for human probiotics. Digestibility is the % of food that humans can absorb. [It also means how much time I need to digest food] A sourdough product is more digestible than other products (bakers' yeasts product). In the study to confirm that they recruited people and administered a slice of sourdough bread and a slice of bakers' yeast bread and after that monitored.

thedigestibility.They made the bread and gave it to the panelists.They asked people about their opinion after the ingestion (appetite, satiety, gastrointestinal symptoms suchas nausea and fullness). But they also used medical ultrasound (ecografia) to monitor the time of transferring.When the digestion is difficult there’s an emission of gas: they used an instrument to monitor the emission ofhydrogen. They determined the concentration of free aa.The results have shown that sourdough bread has a fastertransit, no emission of hydrogen, higher intake of nutrients andlower glycemia.

Fermented vegetables and fruitsPlants can provide a variety of nutrients and are therefore attractive hosts for microorganisms.We can distinguish between microbes that live on the surface of the plant (epiphytes) and microbes livingwithin the plant tissues and these are called endophytes.Epiphytes are most abundant and the their variation is higher.The epiphytic microbial population of plants is largely

subjected to fluctuations of the physical and nutritional conditions. Each species of fruits and vegetables have a dominant and constant microbiota. LAB are naturally present in fruits and vegetables, there's an abundant population and LAB belong to it. The microbial population of raw vegetables and fruits fluctuates between 10^2 and 10^10 cfu/g: - Yeasts range between 10^2 and 10^6 cfu/g (i.e., Cryptococcus, Candida, Saccharomyces, Pichia, Hansenula, Debaromyces and Rhodotorula). - Bacteria aerobes (Pseudomonas, Enterobacteriacee and Coryneforms). Coagulase-positive staphylococci and other faecal bacteria. - LAB 10^2 - 10^4 cfu/g. On the surface (out-layer) of plants and vegetable it's easier to found aerobic microbes meanwhile in the inside it's easier to find anaerobic microbes. Traditional vegetable and fruit fermentation is seen as cultural heritage in most regions of the world. Fermentation of vegetables and fruits is a way diffuse worldwide to conserve food. LAB fermentation is.the pH. This is achieved by the addition of lactic acid bacteria, the main microorganisms responsible for the fermentation process. These bacteria convert the sugars present in the vegetables into lactic acid, which lowers the pH and creates an acidic environment that inhibits the growth of harmful bacteria. During fermentation, the lactic acid bacteria produce various compounds that contribute to the unique flavor and aroma of kimchi. These compounds include lactic acid, acetic acid, ethanol, and various volatile compounds. The fermentation process also leads to the production of carbon dioxide, which creates the characteristic fizzy texture of kimchi. After fermentation, the kimchi is typically stored in the refrigerator to slow down the fermentation process and preserve its flavor. It can be consumed immediately or aged for a certain period of time to further develop its flavor. In conclusion, kimchi is a traditional Korean fermented vegetable dish that undergoes a natural fermentation process without any heating treatment. It is made by cutting and brining the vegetables, washing off the excess salt, blending the ingredients, and fermenting them for a certain period of time. The lactic acid bacteria play a crucial role in the fermentation process, converting sugars into lactic acid and creating the unique flavor and texture of kimchi.the final product can occur. - The growth of pathogenic bacteria cannot be completely controlled. - The fermentation process may not reach the desired level of acidity. To mitigate these risks, it is important to carefully select and handle the vegetables, control the salt concentration, monitor the pH and temperature, and ensure proper hygiene and sanitation practices throughout the fermentation process. Additionally, using starter cultures of specific lactic acid bacteria can help to standardize and control the fermentation process, resulting in a more consistent and safe final product.the sensory, nutritional and rheology properties. ATTENZIONE: non modificare il testo in altro modo, NON aggiungere commenti, NON utilizzare tag h1; Il tuo compito è formattare il testo fornito utilizzando tag html. ATTENZIONE: non modificare il testo in altro modo, NON aggiungere commenti, NON utilizzare tag h1;

the sensory, nutritional and rheology properties.

Fermentation failure: it could stop for climate changes etc;

Inadequate inhibition of spoilage and pathogen microorganisms.

How to control the fermentation?

→Using commercial starters (allochthonous) isolated form certain raw matrices but used to ferment various products.

→autochthonousUsing starters isolated from and re-used on the same raw matrix, apart from the geographical origin);

→back-sloppingUsing the technique inoculation with a small amount of a previously and successfully fermented raw material. Fermentation of tomato’s juice

Increase of the number of autochthonous and allochthonous.

There’s a decrease of the pH in both. They naturally stay in the plant, they’ve the capability to adapt to the environmental condition of the plant.

The consuming of fruit and vegetables can be fresh or after processing, most of the times there’s a thermal treatment that has the priority to get the consumption of

a certain fruit/vegetable far from the season in which they're normally growing but it has repercussions on the sensory and rheology characteristics of the product but also on the nutritional one. The fermentation allow us to decrease the thermal treatment or avoid it because of the decrease of the pH. So the product obtained it's closer to a fresh product. It allows to keep the sensory characteristics of a fresh product. Fruit is an hostile environment- The main difference between fruit and vegetables is that vegetables are less acid, the pH closer to the neutrality whereas fruit has a lower pH, very acid substrate. LAB prefer a pH closer to the neutrality. Extremely acid environment.- Fruit has a high concentration of fructose and glucose: a high concentration of sugars may affect the available content of water (If Aw is low, microbes can't grow).[1have a capability to survive to infection inherent presence of anti-microbial compounds.

The presence of anti-nutritional factors.

Presence of nutrients (fibres) when they’ve a very high concentration they have the capability to inhibit the growth of microbes.

Example of a biotechnology protocol to ferment raw vegetables and fruits

Take a raw material, isolate and Typing: the differentiation to know different features, identification to give a name to the microbes.

Select the best performing starters. Selection based on technological, nutritional and sensory criteria.

[In general three-four strains are better than just one: one of them will be successful]

Processing the raw material in different shapes (juice, pieces, puree). Eventually depends on the final pH: if the final pH is very low (lower than 4.5 in a rapid time) the thermal treatment can be avoided.

Inoculum of the starter at a final cell density 10 cfu/g -7 starting with the 10 in order to achieve 10 to have an 7 9 increase of 2

Logs cycles if the conditions are suitable][10 10 10 .→ →9 7 9

LAB fermentation.Storage at 4°C; if not refrigerating fungi might grow

Bio-preservation means: preservation of a food avoiding chemical preservatives and thermal processes. It’s an important biotechnology to maintain and/or improve the nutritional and sensory features and health properties.

Smoothies

Smoothie is a mixture of fruit and / or vegetables, transformed into puree, often after the removal of seeds and peel. They’re an alternative to the consumption of fresh fruit and vegetables to meet the recommended daily fruit and vegetable ration (2-4 serving per day).

The most attractive characteristic for consumers is the colour. Playing with different fruit to get an attractive colour for consumers is crucial.

Protocol for Fermentation and Storage of Red and Green Smoothies

As a general rule pasteurisation is a thermal treatment below 100°C (if higher is a sterilisation) but different condition of T and

T are applied to keep the best nutritional properties of a food. T/t to get a pasteurisation are changed according to the chemical composition (Maillard reaction, enzymes etc.) of the food; the goal is always the same: inhibit the growth of pathogens so hygiene but keeping nutritional properties.

The viscosity is higher in started and lower in un-started. The viscosity is given by EPS during LAB fermentation (starters have the capability to synthesis EPS)

Recycling by-products is the new trend nowadays. People want to buy just perfect fruit with no damages nor imperfection so the goal nowadays is to find a way to reuse the unsold products. Smoothies is a good possibility to use the unsold fruits.

Sensory evaluation of red and green smoothies:

Conclusions:

The fermentation of smoothies at 25°C for 24 hours using the autochthonous mixed starter of lactic bacteria guarantees:

• The preservation of the colour and a slowdown of browning during storage
• Preservation of antioxidant compounds

1. (ascorbic acid and phenolic compounds) spring storage;
2. increased anti radical activity;
3. better rheological properties;
4. desirable sensory attributes;
5. probiotic potentials.

Alcoholic fermentation (Wine-making)

To complete the fermentation in wine making all the sugars have to be fermented in ethanol.

Two goals: to complete the fermentation and to have a peculiar aroma.

I. Yeasts found in musts, many of which are responsible for starting but not completing the fermentation process. These are yeasts that start but then not complete the fermentation because they're inhibit by alcohol [Remember: Kloeckera and Pichia];

II. Yeasts able to complete the fermentation process: S. cervisiae;

III. Yeasts used in suc