Saturday, November 14, 2015

Fermentasi



Since fruits ferment naturally, fermentation precedes human history. However, humans began to take control of the fermentation process at some point. There is strong evidence that people were fermenting beverages in Babylon circa 5000 BC, ancient Egypt circa 3000 BC, pre-Hispanic Mexico circa 2000 BC, and Sudan circa 1500 BC. There is also evidence of leavened bread in ancient Egypt circa 1500 BC and of milk fermentation in Babylon circa 3000 BC. The Chinese were probably the first to develop vegetable fermentation.

Throughout human history, bacteria and fungi have been intimately involved with both the success and failure of daily life. Microorganisms cause disease, but they also play a wider role in sustaining life. We know that certain bacteria play a major part in recycling chemical elements as well as compounds. For example, bacteria help return the materials of dead organisms back to the earth, so those materials can be used by living organisms. What's more, without bacterial action, living things would not be able to use certain compounds found in soil, water, and even the atmosphere. Modified versions of these microorganisms are now essential in modern day pharmaceutical production.
In fermentation, microorganisms such as bacteria, yeasts, and molds are mixed with ingredients that provide them with food. As they digest this food, the organisms produce two critical by-products, carbon dioxide gas and alcohol.

Discovery of the fermentation process allowed early peoples to produce foods by allowing live organisms to act on other ingredients. But our ancestors also found that, by manipulating the conditions under which the fermentation took place, they could improve both the quality and the yield of the ingredients themselves.
  
Fermentation is one of the oldest ways humans have used microbes. Fermentation enhances the nutrient content of foods through the biosynthesis of vitamins, essential amino acids and proteins, by improving protein and fibre digestibility, by enhancing micronutrient bioavailability, and by degrading antinutritional factors. It also provides a source of calories when used in the conversion of substrates, unsuitable for human consumption, to human foods.

Fermentation is carried out by both bacteria (prokaryotes) and fungi (eukaryotes) during their metabolism. Both groups of organisms also figure in the world of human disease, as they are both sources of antibiotics, as we'll see throughout this module. Fermentation results in a number of byproducts that have many different uses. As mentioned, the most well-known product of fermentation is ethyl alcohol. This substance is both a beverage as well as a starter molecule for synthesizing other compounds. Since fermentation is carried out in the absence of oxygen, we call it an anaerobic process. It is a method by which organisms such as yeast obtain their energy by converting sugars into other chemical compounds, particularly carbon dioxide and water. Interestingly, our bodies also use this same anaerobic fermentation to obtain energy from sugars when oxygen is in low supply in our blood, such as during vigorous exercise. The products of this process are lactic acid and water rather than the carbon dioxide and water that human metabolism normally produces. In this day and age, pharmaceutical companies utilize the fermentation carried out by microorganisms to produce antibiotics, hormones, and specialized proteins such as antibodies and insulin (Fermentation processes enhance food safety by reducing toxic compounds such as aflatoxins and cyanogens, and producing antimicrobial factors such lactic acid, bacteriocins, carbon dioxide, hydrogen peroxide and ethanol which facilitate inhibition or elimination of food-borne pathogens). This wide range of products is possible because the bacterium or fungus involved in fermentation has been genetically changed to produce a specific substance. Therapeutic properties of fermented foods have also been reported.

In addition to its nutritive, safety and preservative effects, fermentation enriches the diet through production of a diversity of flavors, textures and aromas. It improves the shelf-life of foods while reducing energy consumption required for their preparation. The production of fermented foods is also important in adding value to agricultural raw materials, thus providing income and generating employment.

Traditional fermentation processing is generally a spontaneous, non-aseptic operations which result from the competitive activities of a variety of microorganisms. In a bioreactor - which may consist of clay or metal pots, a basket, or a simply hole in the ground lined with leaves - strains best adapted, and with the highest growth rates, dominate under uncontrolled conditions. Optimization of process controls and of the microbial flora associated with fermentations therefore poses one of the biggest challenges in improving food fermentation technologies. Appropriate quality control methodologies - e.g. use of high quality raw materials, proper hygienic standards in the processing environment, proper packaging - also need to be developed.

Improvements in process control through the development of more appropriate bioreactors, particularly those suitable for solid substrate fermentations, could improve the quality and quantity of fermented foods available in developing countries. The selection and development of more productive microbial strains, and the control and manipulation of culture conditions could also increase the efficiency of fermentation processes. 

Processing

Fermentation is a process that is important in anaerobic conditions when there is no oxidative phosphorylation to maintain the production of ATP by glycolysis. During fermentation pyruvate is metabolised to various different compounds. Textbook examples of fermentation products are ethanol (drinkable alcohol), lactic acid, and hydrogen. However, more exotic compounds can be produced by fermentation, such as butyric acid and acetone.

Although the final step of fermentation (conversion of pyruvate to fermentation end-products) does not produce energy, it is critical for an anaerobic cell since it regenerates nicotinamide adenine dinucleotide (NAD+), which is required for glycolysis. This is important for normal cellular function, as glycolysis is the only source of ATP in anaerobic conditions.

Fermentation products contain chemical energy (they are not fully oxidised) but are considered waste products since they cannot be metabolised further without the use of oxygen (or other more highly-oxidised electron acceptors). A consequense is that the production of ATP by fermentation is less efficient than oxidative phosphorylation, where pyruvate is fully oxidised to carbon dioxide. Fermentation produces two ATP molecules per molecule of glucose compared to approximately 36 by aerobic respiration. Even in vertebrates, however, it is used as an effective means of energy production during short, intense periods of exertion, where the transport of oxygen to the muscles is insufficient to maintain aerobic metabolism. In humans, for example, lactic acid fermentation provides energy for a period ranging from 30 seconds to 2 minutes. The speed at which ATP is produced is about 100 times that of oxidative phosphorylation. The pH in the cytoplasm quickly drops when lactic acid accumulates in the muscle, eventually inhibiting enzymes involved in glycolysis.

The fermentation process is caused by enzymes, catalysts in chemical reactions similar to the digestive enzymes in the human body. Certain enzymes act on starch to break down the long chain-like molecules into smaller units of sugar. Then other enzymes convert one kind of sugar molecule to another. Still other enzyme reactions break apart the sugar molecule (composed of carbon, hydrogen and oxygen) into ethyl alcohol and carbon dioxide gas.
The production of carbon dioxide and alcohol are incidental to the release of energy needed by organisms such as yeast to survive. But these metabolic by-products have been used in human enterprise for centuries. The yeast Saccharomyces cerevisiae is traditionally added to liquids derived from grains and fruits to brew beer and wine. The natural starches and sugars provide food for the yeast and during fermentation the desired alcohol is released. In China for thousands of years, traditional soy sauce or shoyu was brewed by adding the fungus Aspergillus oryzae to a mixture of boiled soybeans and wheat and allowing it to ferment for about a year.
In recent times, yeasts have been used to aid in the production of alternative energy sources. Yeasts are placed in large fermentation vats containing organic material. During fermentation the yeast convert the organic material into ethanol fuel. Researchers are working on developing yeast strains that will convert even larger organic biomasses into ethanol more efficiently.
Products

Products produced by fermentation are actually waste products produced during the reduction of pyruvate to regenerate NAD+ in the absence oxygen.
  • Ethanol fermentation (done by yeast and some types of bacteria) breaks the pyruvate down into ethanol and carbon dioxide. It is important in bread-making, brewing, and wine-making. When the ferment has a high concentration of pectin, minute quantities of methanol can be produced. Usually only one of the products is desired; in bread the alcohol is baked out, and in alcohol production the carbon dioxide is released into the atmosphere.
  • Lactic acid fermentation breaks down the pyruvate into lactic acid. It occurs in the muscles of animals when they need energy faster than the blood can supply oxygen. It also occurs in some bacteria and some fungi. It is this type of bacteria that convert lactose into lactic acid in yogurt, giving it its sour taste.
The burning sensation in muscles during hard exercise used to be attributed to the production of lactic acid during a shift to anaerobic glycolosis, as oxygen is converted to carbon dioxide by aerobic glycolysis faster than the body can replenish it; but muscle soreness and stiffness after hard exercise is actually due to microtrauma of the muscle fibres. The body falls back on this less-efficient but faster method of producing ATP under low-oxygen conditions. This is thought to have been the primary means of energy production in earlier organisms before oxygen was at high concentration in the atmosphere and thus would represent a more ancient form of energy production in cells. The liver later gets rid of this excess lactate by transforming it back into an important glycolysis intermediate called pyruvate. Aerobic glycolysis is a method employed by muscle cells for the production of lower-intensity energy over a longer period of time.
Bacteria generally produce acids. Vinegar (acetic acid) is the direct result of bacterial fermentation. In milk, the acid coagulates the casein, producing curds. In pickling, the acid preserves the food from pathogenic and putrefactive bacteria.

Uses

The primary benefit of fermentation is the conversion, e.g., converting juice into wine, grains into beer, and carbohydrates into carbon dioxide to leaven bread.
According to Steinkraus (1995), food fermentation serves five main purposes:
  1. Enrichment of the diet through development of a diversity of flavors, aromas, and textures in food substrates
  2. Preservation of substantial amounts of food through lactic acid, alcoholic, acetic acid, and alkaline fermentations
  3. Biological enrichment of food substrates with protein, essential amino acids, essential fatty acids, and vitamins
  4. Detoxification during food-fermentation processing
  5. A decrease in cooking times and fuel requirements
Fermentation has some benefits exclusive to foods. Fermentation can produce important nutrients or eliminate antinutrients. Food can be preserved by fermentation, since fermentation uses up food energy and can make conditions unsuitable for undesirable microorganisms. For example, in pickling the acid produced by the dominant bacteria inhibit the growth of all other microorganisms.  

Friday, November 13, 2015

Prebiotic vs Probiotic (2)

Consuming Prebiotic Fiber

chicory-2-high1
Chicory Root has the highest percentage of Prebiotic Fiber per gram

Live probiotic bacteria are easy to find and consume if dairy products are to your taste and meet your dietary needs. Yogurt, for example, contains probiotics; but where can you find prebiotic fiber? It’s easy if you know where to look.
Prebiotic fiber is found in many fruits and vegetables, such as the skin of apples, bananas, onions and garlic, Jerusalem artichoke, chicory root and beans. Sounds easy to get enough prebiotic fiber, right? Unfortunately, the minute amounts of fiber in each of these foods — such as 1 to 2 grams per serving — make ingesting enough fiber extremely difficult. Most people should consume at least 25 grams of fiber every day, and the foods highest in prebiotic fiber — chicory root is one such example — are nearly impossible to eat in large quantities every day. The good news is that adding a prebiotic fiber supplement to your diet is fast and simple. In supplement form, prebiotic fiber is also mild in texture and nearly tasteless, making it easy to add to water, cereal or any other food. Simply sprinkle it on your foods or in your favorite drinks to enjoy the many benefits. 

 

How Prebiotics Help

For years, hardly anyone in the medical profession paid any attention to the role the colon plays in overall health. Over the past 15 years, however, we have discovered that the colon — and specifically, the bacteria that call the colon home — is incredibly important to wellness. The healthy bacteria that live there strengthen the bowel wall, improve mineral absorption and aid in the regulation of hormone production, which has a range of essential benefits. Prebiotics fertilize these good bacteria as they stifle production of the bad, disease-causing bacteria, and prebiotic fiber is independently shown to cause the multiplication of beneficial bacteria which combat gut dysbiosis.
When you have ample beneficial bacteria, you can experience better overall health from a physical, mental and emotional standpoint. You’ll be better nourished, feel fuller, and able to achieve and maintain a healthy weight more easily.

Prebiotic vs Probiotic (1)

Prebiotics are not probiotics.

While the general public has long understood probiotics, prebiotics are less known. But there are significant differences between the two, including health benefits.
 Probiotics are live bacteria in yogurt, other dairy products and pills. Doctors often prescribe probiotics to patients on antibiotics in an attempt to combat gastrointestinal side effects of the medication. And while probiotics have been shown effective in managing certain gastrointestinal conditions, they do not have the same power that prebiotics do.
First, they’re delicate — heat and stomach acid can kill them, rendering them ineffective before they’ve even been digested. Also, those who don’t eat dairy foods for taste or dietary reasons may find ingesting adequate amounts of probiotics difficult, if not impossible. Finally, we don’t know which “good” bacteria our unique bodies would benefit from. For some people, a certain good bacterial strain would be helpful. For others, it may not. When we consume probiotics, we’re taking a guess at which bacteria might be helpful and hoping for the best. We’re also hoping the ones that make it past the heat and acid of our stomach will actually go on to provide some health benefits to our system.
If this is a probiotic then what is a prebiotic? In short, the prebiotic is a specialized plant fiber that beneficially nourishes the good bacteria already in the large bowel or colon. While probiotics introduce good bacteria into the gut, prebiotics act as a fertilizer for the good bacteria that’s already there. They help your good bacteria grow, improving the good-to-bad bacteria ratio. This ratio has been shown to have a direct correlation to your health and overall wellbeing, from your stomach to your brain.
The body itself does not digest these plant fibers. Instead, it uses these fibers to promote the growth of many of the good bacteria in the gut. These, in turn, provide many digestive and general health benefits. Recent studies have also shown prebiotics and good bacterial gut balance play a direct role in mental health. Individuals who consume prebiotics on a daily basis have fewer issues with anxiety, depression and stress. In fact, when their saliva was tested, it contained lower levels of cortisol. High levels of this hormone have been linked directly to mental health disorders.
Prebiotics, unlike probiotics, are not destroyed in the body. They are not affected by heat or bacteria. Getting the full benefits of prebiotics is easy, especially when consumed in a full-spectrum supplement form.
Prebiotin is the only full-spectrum prebiotic on the market. This means the Prebiotin formula of prebiotic supplements contains both inulin and oligofructose. This full spectrum formula treats the entire bowel wall for maximum effectiveness. And Prebiotin has been proven by numerous independent scientific studies to increase the number of healthy bacteria in the colon, the benefits of which are impressive and essential to overall health and well being.


Probiotic vs Prebiotic

Prebiotics and probiotics both accomplish important health tasks for the human gut. Trying to decide between a probiotic and prebiotic supplement regimen? Prebiotin prebiotic supplements provide a range of important benefits not just to lower gut health but to overall well being, too. Our formula has been rigorously tested and medically proven to increase the number of healthy bacteria in the gut. Science has proven the health benefits of prebiotics include increased bone density, strengthened immune system, better-controlled weight and appetite, and improved bowel regularity. Recent studies have also found that individuals taking prebiotics experience improved mental health.
Consider these prebiotics vs probiotics facts:


PREBIOTIC VS PROBIOTIC
PREBIOTICS
PROBIOTICS
PREBIOTICS are a special form of dietary fiber that acts as a fertilizer for the good bacteria in your gut. PROBIOTICS are live bacteria in yogurt, dairy products and pills. There are hundreds of probiotic species available. Which of the hundreds of available probiotics is best for the average healthy person is still unknown.
PREBIOTIC powders are not affected by heat, cold, acid or time. PROBIOTIC bacteria must be kept alive. They may be killed by heat, stomach acid or simply die with time.
PREBIOTICS provide a wide range of health benefits to the otherwise healthy person. Most of these have been medically proven. PROBIOTICS are still not clearly known to provide health benefits to the otherwise healthy. Some are suspected but still not proven.
PREBIOTICS nourish the good bacteria that everyone already has in their gut. PROBIOTICS must compete with the over 1000 bacteria species already in the gut.
PREBIOTICS may be helpful for several chronic digestive disorders or inflammatory bowel disease. Certain PROBIOTIC species have been shown to be helpful for childhood diarrhea, irritable bowel disease and for recurrence of certain bowel infections such as C. difficile.

Notes