[001] The current invention relates to the field of enhancing nutritive value of whole wheat flour. The invention relates to method of producing whole wheat flour which contains higher amounts of Non-starch polysaccharides, resistant starch and fibre, and has much lesser microbial contamination compared to whole wheat flour made by conventional methods, hence the resulting flour has more nutritive value, longer shelf-life and is a healthy food option.

BACKGROUND
[002] Many challenges are faced by millers and food industries alike in relation to production of whole wheat flour due to its limited stability and loss of nutritive value while processing, in comparison to refined flour. Lipid degradation by the enzymatic action as well as non-enzymatic pathways seems to be a one of the leading cause of stability issues of whole wheat flour. Milling technique used is of paramount importance to produce whole wheat flour. To address the stability issues, retention of available antioxidant during milling and inactivation of enzymes can be explored along with wheat bran stabilization. The purpose of this invention is to address these key issues in milling, shelf-life, key biomarkers of whole wheat flour and finally discuss the strategies to overcome existing challenges.
[003] High fibre content of whole wheat flour is based upon the content of Non-starch Polysaccharides and Resistant starch. Conventional milling techniques like stone milling and roller milling damage nutritive content like starch, non-starch Polysaccharides, resistance starch and protein. Stone mills are the oldest attrition mills used for making whole grain flours, which simultaneously use compression, shear, and abrasion to grind wheat kernels between two stones and produce a theoretical extraction rate of 100%. Modern stone mills are metal plates with composition stones attached. Stone mills generate considerable heat due to friction. Most whole wheat flour brands available in the market are manufactures using stone milling. The process of roller milling involves separation of the endosperm from the bran and germ followed by gradual size reduction of endosperm and involves passing wheat grains through a series of corrugated and smooth rollers accompanied by sifting between stages. Thus, by using roller milling, wheat bran is removed in the process, and the wheat flour produced does not retain the nutritive and dietary fibre content of whole wheat flour.
[004] Non-starch Polysaccharide (NSP) content of wheat flour is an indicator of use of whole wheat grains in manufacturing whole wheat flour. The non-starch polysaccharides of whole wheat flour are rich in arabinose, xylose, and glucose compared to white flour, and these sugars are largely derived from the polysaccharides of the bran layers. About 70% of the non-starch polysaccharide content of whole wheat flour is due to the presence of the wheat bran.
[005] Resistant starch (RS) is a type of fermentable fibre that is very beneficial to the human body. It provides food for the good bacteria in the gut, which metabolize it into butyric acid, the main fuel source for colon cells enabling optimal function of colon cells. (Akerberg et al ,1998, The Journal of Nutrition, Volume 128, Issue 3, March 1998, Pages 651–660). RS is very sensitive to dry heat and its content decreases sharply with increasing heat as a result of friction upon grinding by making use of modern machines or powered stone grinding that generates temperature as high as 80°C. Such wheat flour contains very low amount of RS i.e. just 2% or less leading to severe health problem particularly causes constipation.
[006] The current invention relates to enhancing the nutritive value and dietary fibre of whole wheat flour using novel methods involving milling of the whole wheat grains at lower temperature compared to conventional milling techniques. The methods of the invention result in retention of nutritive value as well as enhancement of nutritive value of whole wheat flour by retaining non-starch polysaccharides and increasing RS content respectively.

SUMMARY OF THE INVENTION
[007] The current invention relates to a method of producing whole wheat flour comprising the step of milling wheat by pressing and disintegrating wheat grains using a rotating mill process, at a temperature maintained below 40° C. The method of the invention retains nutritive value of whole wheat flour.
[008] In one embodiment of the invention, the method further comprises the step of subjecting the whole wheat flour produced by the method described above, to heating-freezing cycles to increase resistant starch content in the whole wheat flour. In one embodiment of the invention ,the heating –freezing cycle is done by subjecting the whole wheat flour to alternating steps of wet heating with superheated steam at a temperature range of 230 -236° C for 15-25 seconds and freezing step at a temperature range of -16° C to -20°C, wherein the entire heating-freezing cycle is done for 20-24 hours.
[009] In one embodiment of the invention, the whole wheat flour with high resistant-starch has at most 2-fold increase in resistant starch when compared to whole wheat flour which has not been subjected to heating-freezing cycles. In one embodiment of the invention, the resistant starch content of the whole wheat flour is increased from 14% to a maximum of 22.79%.
[010] In one embodiment of the invention, the non-starch polysaccharides are retained in the whole wheat flour after milling. In one embodiment of the invention, the non-starch polysaccharide content in the whole wheat flour is at least 10%.
[011] In one embodiment of the invention, the whole wheat flour produced by the disintegration technique described herein contains substantially more vitamins, minerals, antioxidants and other nutrients than regular wheat flour.
[012] In one embodiment of the invention, the method of producing whole wheat flour further comprises the step of washing the wheat grains used for producing the whole wheat flour with ozonated water.
[013] One embodiment of the invention is a whole wheat flour composition produced from milling wheat by pressing and disintegrating wheat grains at a temperature maintained below 40° C. In one embodiment of the invention, the whole wheat flour composition is produced from subjecting the whole wheat flour produced by pressing and disintegrating wheat grains at a temperature maintained below 40°C to heating-freezing cycles to increase resistant starch content in the whole wheat flour. One embodiment of the invention is the whole wheat flour composition produced from wheat grains that have been washed with ozonated water.
[014] In one embodiment of the invention, (RS) content of the whole wheat flour composition is more than 14 %. In one embodiment of the invention, non-starch polysaccharide (NPS) content of the whole wheat flour composition is at least 10%. In one embodiment of the invention, the wheat grains used for producing whole wheat flour of the invention are matured in 100% sunny days.
[015] In one embodiment of the invention, the whole wheat flour composition has at least 80% less microbial contamination than whole wheat flour produced without washing with ozonated water.
[016] In one embodiment of the invention, the whole wheat flour composition of the invention enhances butyrate production in the colon and promotes growth of healthy bacteria in the gut.
[017] One embodiment of the invention is an edible product made from the whole wheat flour composition of the invention. In one embodiment of the invention, the edible product is, without limitation, a bakery product, a snack product or a food product.

BRIEF DESCRIPTION OF THE FIGURES

[018] The above-mentioned and other features and advantages of this present disclosure, and the manner of attaining them, will become more apparent and the present disclosure will be better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein:

Figure 1: Illustrates a flowchart depicting the process of producing whole wheat flour with high content of Non-Starch Polysaccharides, fibre, resistant starch, vitamins and antioxidants.

DETAILED DESCRIPTION
[019] The current invention relates to a method for producing whole wheat flour that retains high nutritive value of whole wheat grains. The invention relates to method of producing whole wheat flour which contains higher amounts of Non-starch polysaccharides, resistant starch and fibre, and has much lesser microbial contamination compared to whole wheat flour made by conventional methods, hence the resulting flour has more nutritive value, longer shelf-life and promotes growth of healthy bacteria in the gut.
[020] Definitions:
[021] As used herein, "Non-Starch Polysaccharides" (NSP) are compounds that correspond to dietary fibre and occur naturally in various foods. Their properties like water dispersibility, viscosity effect, bulk, and fermentability into short chain fatty acids has significant impact on physiological functions. These compounds enable optimal gut function, lower cholesterol, regulate blood glucose and are important for human health. (Kumar et al, 2012, Dietary roles of non-starch polysaccharides in human nutrition: a review, 2012;52(10):899-935).

[022] As used herein, "Resistant Starch" (RS) are compounds that are not digested in the small intestine and are passed to the larger intestine. RS is a good substrate for fermentation to produce short chain fatty acids. RS confers health benefits by regulating metabolism and stabilizing blood glucose, lowering cholesterol, increasing satiety.RS as used herein includes RS1, RS2, RS3 and RS4. (Higgins et al, 2004, Resistant starch: metabolic effects and potential health benefits, 2004 May-Jun;87(3):761-8)
[023] RS3 is a version of resistant starch, non-granular in nature, formed when starch is subjected to heating and freezing cycles and confers various health benefits by regulating metabolism and stabilizing blood glucose, lowering cholesterol, increasing satiety (Birt et al, 2013, Resistant Starch: Promise for Improving Human Health, 2013 Nov; 4(6): 587–601).

[024] As used herein "Pressing and Disintegrating technique" technique for milling wheat grains refers to the process wherein wheat grains are pressed and disintegrated by a process of rotating mills. The resulting whole wheat flour contains substantially more vitamins, minerals, antioxidants and other nutrients than regular wheat flour, since these compounds are concentrated in the outer portion of the grain. There is minimal or no loss of this outer portion of the wheat grain by using this milling technique and the same is retained significantly in the resultant whole wheat flour.

[025] As used herein, "Ozonated water" is the liquid form generated when ozone is dissolved in saline and has significant antimicrobial effects. It is frequently used to reduce contaminants, especially microbial contaminants in various fields including medicine and food. With ozone being a gas form, ozonated water is easier to handle and use (Kuroda et al, 2018, Use of ozonated water as a new therapeutic approach to solve current concerns around antitumor treatment, 2018 Sep; 16(3): 1597–1602).

[026] As used herein "Farinograph" is a test routinely done to assess wheat flour characteristics. It measures resistance of the dough against the mixing actions of the blades and hence determines dough and gluten properties of the flour. The results indicate the amount of water required to make a dough, effects of ingredients on mixing properties, flour blending requirements, and to check flour uniformity. The results are also used to predict processing effects, including mixing requirements for dough development, tolerance to over mixing, and dough consistency during production, texture of the finished product.
[027] As used herein "Extensigraph" is a test where the force required to stretch the dough with a hook until it breaks is measured and is indicator of resistance and extensibility of dough. The test determines the dough strength and elasticity.

[028] Embodiments:

[029] One embodiment of the invention is a method of producing whole wheat flour comprising the step of milling wheat by pressing and disintegrating wheat grains using a rotating mill process, at a temperature maintained below 40° C. In one embodiment of the invention, the method retains nutritive value of whole wheat flour. In one embodiment of the invention, the whole wheat flour produced by the method disclosed herein is made without any significant loss of resistant starch. In one embodiment of the invention, the whole wheat flour produced by the method disclosed herein is made without any significant loss of wheat bran while processing. In one embodiment of the invention, the whole wheat flour produced by the method disclosed herein is made without any significant loss of wheat bran polysaccharides.
[030] In one embodiment of the invention, the method further comprises the step of subjecting the whole wheat flour produced to heating-freezing cycles to increase resistant starch content in the whole wheat flour. In one embodiment of the invention ,the heating –freezing cycle is done by subjecting the whole wheat flour to alternating steps of wet heating with superheated steam at a temperature range of 230 -236° C for 15-25 seconds and freezing step at a temperature range of -16° C to -20°C, wherein the entire cycle is done for 20-24 hours. In one embodiment of the invention, wet heating with superheated steam is at a temperature of 231.1°C for 20 seconds. In one embodiment of the invention, the heating –freezing cycles lead to conversion of native starch to RS3 fibre.
[031] In one embodiment of the invention, the whole wheat flour with high resistant-starch has at most 2-fold increase in resistant starch when compared to whole wheat flour which has not been subjected to heating-freezing cycles. In one embodiment of the invention, the resistant starch content of the whole wheat flour is increased from 14% to at least 20%. In one embodiment of the invention, the resistant starch content of the whole wheat flour is increased from 14% to at least of 22%.
[032] In one embodiment of the invention, the non-starch polysaccharides are retained in the whole wheat flour after milling. In one embodiment of the invention, the non-starch polysaccharide content in the whole wheat flour is at least 10%. In one embodiment of the invention, various non-starch polysaccharides in the whole wheat flour of the invention (2) are listed in Table 2.

Table 1
Non-Starch Polysaccharides (NSP) in Whole wheat flour of the invention Vs. Other whole wheat flour brands:-

[033] In one embodiment of the invention, the wheat grains used for producing the whole wheat flour are matured for at least 100 sunny days.
[034] In one embodiment of the invention, the method of producing whole wheat flour further comprises the step of washing the wheat grains used for producing the whole wheat flour with ozonated water before the step to produce the whole wheat flour. In one embodiment of the invention, the ozonated water used has a concentration of 1.2-2mg/L . In one embodiment of the invention, the ozonated water used has a concentration of 1.5mg/L. In one embodiment of the invention, 2 litres of ozonated water is used per kilogram of wheat grains. In one embodiment of the invention, the whole wheat flour has at least 80% less microbial contamination than whole wheat flour produced without washing with ozonated water. In one embodiment of the invention, the whole wheat flour has at least 90% less microbial contamination than whole wheat flour produced without washing with ozonated water. In one embodiment of the invention, the whole wheat flour has at least 80% less microbial contamination than whole wheat flour produced without washing with ozonated water. In one embodiment of the invention, the whole wheat flour has 99% lesser microbial contamination than whole wheat flour produced without washing with ozonated water. In one embodiment of the invention, the microbial contaminants that are reduced in the whole wheat flour of the invention include, without limitation, bacteria such as E.coli, Bacillus cereus, Salmonella species, yeast, fungi, and mold.

Table 2
Microbial Contaminants in Wheat Flour

Values are means; sample sizes are provided in parentheses. NR = Not reported; ND = not detected.

[035] In one embodiment of the invention, treatment with ozonated water has no effect on the quality of the treated wheat grains and whole wheat flour produced from it. In one embodiment of the invention, treatment with ozonated water has no effect on the whole wheat flour properties such as flour extraction rate, farinograph and extensigraph characteristics (Wheat Marketing Centre Inc., Wheat & Flour Testing Methods) , protein content, resistant starch content, non-starch polysaccharide content and sedimentation volume. In one embodiment of the invention, treatment with ozonated water, leads to slight increase extensibility of the dough made from the whole wheat flour of the invention.
[036] One embodiment of the invention is a method of producing whole wheat flour comprising the step of milling wheat by pressing and disintegrating wheat grains at a temperature maintained below 40°C followed by subjecting the whole wheat flour thus produced to heating-freezing cycles to increase resistant starch content in the whole wheat flour. In one embodiment of the invention ,the heating –freezing cycle is done by subjecting the whole wheat flour to alternating steps of wet heating with superheated steam at a temperature of 231.1°C for 20 seconds and freezing step is at a temperature range of -16° C to -20°C, wherein the entire cycle is done for 23 hours resulting in conversion of native starch to RS3 fibre. In one embodiment of the invention, the step of washing the wheat grains used for producing the whole wheat flour with ozonated water before the step to produce the whole wheat flour. In one embodiment of the invention, the ozonated water used has a concentration of 1.5mg/L.
[037] In one embodiment of the invention, at least 60% of the particles in the whole wheat flour have a particle size of that can pass through a sieve mesh of X. In one embodiment of the invention at least 70% of the particles in the whole wheat flour have a particle size of that can pass through a sieve mesh of X.
[038] One embodiment of the invention is a whole wheat flour composition produced from milling wheat by pressing and disintegrating wheat grains at a temperature maintained below 40° C. In one embodiment of the invention, the whole wheat flour composition is produced from subjecting the whole wheat flour produced by pressing and disintegrating wheat grains at a temperature maintained below 40°C to heating-freezing cycles to increase resistant starch content in the whole wheat flour. One embodiment of the invention is the whole wheat flour composition produced from the wheat grains washed with ozonated water.
[039] In one embodiment of the invention, (RS) content of the whole wheat flour composition is more than 14 %. In one embodiment of the invention, non-starch polysaccharide (NPS) content of the whole wheat flour composition is at least 10%.
[040] In one embodiment of the invention, the whole wheat flour composition has at least 80% lesser microbial contamination than whole wheat flour produced without washing with ozonated water.
[041] In one embodiment of the invention, the whole wheat flour composition of the invention enhances butyrate production in the colon and promotes growth of healthy bacteria in the gut. In one embodiment of the invention, healthy bacteria include Bifidobacterium species.
[042] In one embodiment of the invention, the whole wheat flour composition of the invention enables optimal gut function. In one embodiment of the invention, the whole wheat flour composition of the invention reduces the incidence of constipation. In one embodiment of the invention, the whole wheat flour composition of the invention reduced the incidence of colon cancer.
[043] One embodiment of the invention is an edible product made from the whole wheat flour composition of the invention. In one embodiment of the invention, the edible product is, without limitation, a bakery product, a snack product or a food product.

EXAMPLES

[044] Example 1: Disintegrating Wheat Grains
[045] Whole wheat grains produced in the Thar Desert of Rajasthan which receives more than 100% sunny days were used. Wheat grains were pressed and disintegrated by a process of rotating mill wherein the temperature was maintained below 40°C. Whole wheat flour thus produced by employing disintegration technique contained substantially more vitamins, minerals, antioxidants and other nutrients than regular wheat flour, since these compounds are concentrated in the outer portion of the grain.

[046] Example 2 : Increasing RS by Whole Wheat Flour Subjected to Heating-Freezing Cycles
[047] The wheat flour was heated with superheated steam at a temperature range of 230 -236° C for 15-25 seconds followed by a freezing step at a temperature range of -16° C to -20°C, and the heating-freezing cycle was done for 20-24 hours. Increasing cooking-freezing cycles increased RS from 1.03 to 8.07% during in vitro starch digestion. During in vitro fecal fermentation, increasing cooking-freezing cycles increased short chain fatty acids, mainly propionate. Increases in butyrate were also noted during the first 8h of fermentation. Wheat flour so produced resulted in significant increases in Bifidobacterium during fermentation compared to baseline. Thus, even a slight increase in the RS content of whole wheat flour modulated the metabolic activity of gut microbiota to increase production of beneficial metabolites.

[048] Example 3 : Washing the wheat grains with ozonated water and its effects
[049] During wheat flour manufacturing, wheat grains were washed with ozonated water (1.5 mg/L). In the manufacturing process 1 MT wheat grains were washed with 2KL of ozonated hot water for 30 min, drained, crushed, and dried in a forced-draft oven at 104df to < 12% moisture before milling. This treatment resulted in considerable reduction in total bacteria, yeast and mold compared with a similar water wash. The added advantages of ozonated water wash are, the removal of dirt and dust leading to a lighter colour of the resultant whole wheat flour partly due to refraining from mixing of its finely ground bran in comparison to other flour brands available in the marketplace.

Claims:

1.A method of producing whole wheat flour, the method comprising the step of milling wheat by pressing and disintegrating wheat grains by suing a rotating mill, wherein the temperature is maintained below 40° C during the milling to produce whole wheat flour.
2. The method as claimed in claim 1, wherein the method further comprises the step of subjecting the whole wheat flour produced in claim 1 to heating-freezing cycles to increase resistant starch content in the whole wheat flour to produce whole wheat flour with high resistant-starch content.
3. The method as claimed in claim 2, wherein the heating –freezing cycle is done by subjecting the whole wheat flour to alternating steps of wet heating with superheated steam at a temperature range of 230 -236° C for 15-25 seconds and freezing step at a temperature range of -16° C- -20°C, and wherein the heating-freezing cycle is done for 20-24 hours.
4. The method as claimed in claim 2, wherein the whole wheat flour with high resistant-starch has at most 2-fold increase in resistant starch when compared to whole wheat flour which has not been subjected to heating-freezing cycles.
5. The method as claimed in claim 1, wherein the non-starch polysaccharides are retained in the whole wheat flour after milling.
6. The method as claimed in claim 5, wherein the non-starch polysaccharide content in the whole wheat flour is at least 10 %.
7. The method as claimed in claim 1, wherein the wheat grains used for producing the whole wheat flour are matured for at least 100 sunny days.
8. The method as claimed in claim 1, further comprising the step of washing the wheat grains used for producing the whole wheat flour with ozonated water. Figures
9. The method as claimed in claim 8, wherein the ozonated water has a concentration of 1.5 mg/l.
10. The method as claimed in claim 8, wherein the whole wheat flour has at least 80% less microbial contamination than whole wheat flour produced without washing with ozonated water.