Australian food - a natural preservative, I mean flavour
I came up with a very useful technique in preserving food this week using my natural preservative, Herbal-Active®.
The essential oils and leaf extracts from the culinary herbs I use in my new food flavouring (read natural food preservative) have challenged me over retarding the growth of molds.
But before I get into this, let me give you a quick microbiology course.
Microbiologists use a simple chemical staining test to divide bacteria into two groups which are called gram positive or gram negative. Gram was the guy who described the technique and the qualifier says if the bugs stain or not. This division reflects differences in the cell walls of different bacteria and they are then classified on the shape of the cells, whether the organism forms spores, their method of energy production (aerobic or anaerobic) and nutritional requirements.
Many gram negative bacteria are pathogenic and cause meningitis, gastrointestinal, respiratory, urinary and immune problems. Cholera, typhoid and whooping cough are common diseases cause by gram negative bacteria.
E.coli is probably the most famous bacteria of this group and while we harbour benign strains of E.coli as part of our internal flora (until we excrete them in our faeces), some strains can be more virulent and either make us sick or even kill us. Interestingly, my E.coli can upset your system and vice versa.
Salmonella is also in this group and is generally more of a concern in good food hygiene with food poisoning possible at different virulence levels causing symptoms from diarrhea to typhoid.
The gram positive bacteria can be menacing as well. They vary from the beasts for botulism, tetanus and Golden staph to more inconvenient ailments such as sore throats, boils and belly aches. The lactic acid bacteria are the good guys of the group.
There is also a third group of bacteria which don’t gram stain but should and these include organisms which cause TB and leprosy.
Then there are the yeasts which are often grouped with moulds and classed as fungi. Yeasts are single celled fungi from 2 to 8 times bigger than bacteria whereas moulds are multi-celled and bigger than yeasts and are often visible from their mycelia forming a fine network of hairs over the food on which they can grow.
Fungi (like mushrooms) form spores which are often difficult to destroy during cooking or manufacturing processes and this can become a source of food spoilage when viable spores begin to grow.
So there’s the microbiology lesson. When it comes to food, we need to avoid the pathogenic organisms themselves, their spores and in some cases, even the toxins they can leave behind on poorly stored food which might get cooked destroying the bacteria but not the toxins.
I guess with all these bugs out there and people transferring everything from harmful bacteria to benign (for them) ones which then make us sick, it’s not surprising so many of us get sick when eating out at restaurants or even at a friend’s place. It may not be poor hygiene. Just a simple transfer of bacteria non-family members aren’t yet used to.
So this is where my natural preservative, Herbal-Active® comes in. I won’t elaborate on its efficacy as I did that already in a previous blog. But my development this week solved an important challenge in the food industry:
You see while an addition rate of 0.025 to 0.05% of my natural preservative, Herbal-Active® will stop yeasts in their tracks and obliterate the growth of both gram positive and negative bacteria, the moulds are a little more resilient.
However, test showed that at 0.5% even these fungi brutes succumbed to this uniquely Australian natural preservative. The problem is that at this level, Herbal-Active™ is too strongly flavoured to be used if this were the final concentration. Here’s the way around it which might just work for numerous products:
The product in question was a mixture of a variety of fruit concentrates and powders. Several, which collectively formed 10% of the final formulation were found to be the major sources of mould contamination. These were treated with my natural preservative at 0.5% and left over-night. This time might be able to be reduced to hours and will be tested soon. Once the moulds had been killed, the formula was completed and the natural preservative was diluted to a finished level of 0.05% as the other components were added.
The result was a vastly extended shelf life, moulds, yeasts and bacteria all brought down to extremely low levels or zero.
I’d expect that other products currently dependent on harmful levels of potassium sorbate and sodium benzoate preservatives can be treated in the same way. Consider a dough or batter. The water added generally constitutes more than 90% so the remainder can be treated as above and the flavour effectively diluted away as the formulation is completed.
Another win for Australian functional ingredients.