An efficient fermentation method for the degradation of cyanogenic glycosides in flaxseed

Naturally Occurring Plant Food Toxicants and the Role of Food Processing Methods in Their Detoxification

Some plant foods evolve defense mechanisms to protect themselves from predators by producing inherent chemicals as secondary metabolites such as cyanogenic glycosides, glycoalkaloids, glucosinolates, pyrrolizidine alkaloids, and lectins. These metabolites are beneficial for the plant itself but toxic to other organisms, including human beings. Some of these toxic chemicals are believed to have therapeutic benefits and are therefore used to protect against chronic health complications such as cancer. Inversely, short- and long-term exposure to significant amounts of these phytotoxins may end up with chronic irreversible negative health problems in important organ systems, and in severe cases, they can be carcinogenic and fatal. A systematic literature search of relevant published articles indexed in Google Scholar®, PubMed®, Scopus®, Springer Link®, Web of Science®, MDPI®, and ScienceDirect databases was used to obtain the necessary information. Various traditional and emerging food-processing techniques have been found to considerably reduce most of the toxicants in the food to their safest level. Despite their ability to preserve the nutritional value of processed foods, emerging food processing methods have limited application and accessibility in middle- and low-income countries. As a consequence, much more work is recommended on the implementation of emerging technologies, with additional scientific work on food processing methods that are effective against these naturally occurring plant food toxicants, particularly pyrrolizidine alkaloids.

Composition, processing, and quality control of whole flaxseed products used to fortify foods

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid-amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.

A review of flaxseed lignan and the extraction and refinement of secoisolariciresinol diglucoside

Lignan is a class of diphenolic compounds that arise from the condensation of two phenylpropanoid moieties. Oilseed and cereal crops (e.g., flaxseed, sesame seed, wheat, barley, oats, rye, etc.) are major sources of plant lignan. Methods for commercial isolation of the lignan secoisolariciresinol diglucoside (SDG) are not well reported, as most publications describing the detection, extraction, and enrichment of SDG use methods that have not been optimized for commercial scale lignan recovery. Simply scaling up laboratory methods would require expensive infrastructure to achieve a marketable yield and reproducible product quality. Therefore, establishing standard protocols to produce SDG and its derivatives on an industrial scale is critical to decrease lignan cost and increase market opportunities. This review summarizes the human health benefits of flaxseed lignan consumption, lignan physicochemical properties, and mammalian lignan metabolism, and describes methods for detecting, extracting, and enriching flaxseed lignan. Refining and optimization of these methods could lead to the development of inexpensive lignan sources for application as an ingredient in medicines, dietary supplements, and other healthy ingredients.

A comprehensive review of flaxseed (Linum usitatissimum L.): health-affecting compounds, mechanism of toxicity, detoxification, anticancer and potential risk

Flaxseed consumption (Linum usitatissimum L.) has increased due to its potential health benefits, such as protection against inflammation, diabetes, cancer, and cardiovascular diseases. However, flaxseeds also contains various anti-nutritive and toxic compounds such as cyanogenic glycosides, and phytic acids etc. In this case, the long-term consumption of flaxseed may pose health risks due to these non-nutritional substances, which may be life threatening if consumed in high doses, although if appropriately utilized these may prevent/treat various diseases by preventing/inhibiting and or reversing the toxicity induced by other compounds. Therefore, it is necessary to remove or suppress the harmful and anti-nutritive effects of flaxseeds before these are utilized for large-scale as food for human consumption. Interestingly, the toxic compounds of flaxseed also undergoes biochemical detoxification in the body, transforming into less toxic or inactive forms like α-ketoglutarate cyanohydrin etc. However, such detoxification is also a challenge for the development, scalability, and real-time quantification of these bioactive substances. This review focuses on the health affecting composition of flaxseed, along with health benefits and potential toxicity of its components, detoxification methods and mechanisms with evidence supported by animal and human studies.

Bioprocessing of Functional Ingredients from Flaxseed

Flaxseeds (Linum usitatissimum L.) are oilseeds endowed with nutritional constituents such as lignans, lipids, proteins, fibre, carbohydrates, and micronutrients. Owing to their established high nutritional profile, flaxseeds have gained an established reputation as a dietary source of high value functional ingredients. Through the application of varied bioprocessing techniques, these essential constituents in flaxseeds can be made bioavailable for different applications such as nutraceuticals, cosmetics, and food industry. However, despite their food and health applications, flaxseeds contain high levels of phytotoxic compounds such as linatine, phytic acids, protease inhibitors, and cyanogenic glycosides. Epidemiological studies have shown that the consumption of these compounds can lead to poor bioavailability of essential nutrients and/or health complications. As such, these components must be removed or inactivated to physiologically undetectable limits to render flaxseeds safe for consumption. Herein, critical description of the types, characteristics, and bioprocessing of functional ingredients in flaxseed is presented.

A β-glucosidase-producing M-2 strain: Isolation from cow dung and fermentation parameter optimization for flaxseed cake

Flaxseed cake contains cyanogenic glucosides, which can be metabolized into hydrocyanic acid in an animal's body, leading to asphyxia poisoning in cells. Beta-glucosidase is highly efficient in degrading cyanogenic glucosides. The Cattle may have β-glucosidase-producing strains in the intestinal tract after eating small amounts of flaxseed cake for a long time. This study aimed to isolate of a strain from cow dung that produces β-glucosidase with high activity and can significantly reduce the amount of cyanogenic glucosides. We used cow dung as the microflora source and an esculin agar as the selective medium. After screening with 0.05% esculin and 0.01% ferric citrate, we isolated 5 strains producing high amounts of β-glucosidase. In vitro flaxseed cake fermentation was fermented by these 5 strains, in which the strain M-2 exerted the best effect (P < 0.05). The strain M-2 was identified as Lichtheimia ramosa and used as the fermentation strain to optimize the fermentation parameters by a single factor analysis and orthogonal experimental design. The optimum condition was as follows: inoculum size 3%, water content 60%, time 144 h, and temperature 32 °C. Under this condition, the removal rate of cyanogenic glucosides reached 89%, and crude protein increment reached 44%. These results provided a theoretical basis for the removal of cyanogenic glucosides in flaxseed and the comprehensive utilization of flaxseed cake.

Ethnopharmacological values of cassava and its potential for diabetes and dyslipidemia management: Knowledge survey and critical review of report

Background:

Beyond nutritional values are the pharmacological potentials of cassava comparative with other staple carbohydrate plant-based foods such as wheat. The knowledge of applicability to diabetes and its cardiovascular complications management seems not just limited but unacknowledged. As a preliminary study, a community’s knowledge of pharmacological value of cassava is investigated.

Methods:

Descriptive observational study using questionnaire-based “cross-sectional” survey was conducted. 136 Participants completed the survey and 101 respondents were selected for evaluation. Open-ended questions were used qualitatively to generate experience and view cassava values for diabetes and dyslipidemia. While categorical (yes or no) questions were used quantitatively to generate numerical results for diabetes, critical reanalysis of a report data was performed, especially comparing carbohydrate/fiber and fat/fiber ratios of cassava with wheat in view of dyslipidemia.

Result:

On the positive side, 42% of the participants believe that cassava has medicinal values. This includes 6% (among the 42) who believes that the plant is useful in treating diabetes and 24% who do not know it may be useful in diabetes management. Critical review showed that cassava may contribute up to sixteen times more fiber and four times less digestible sugar, as well as carbohydrate/fiber and fat/fiber ratios being 14 and 55 times less than wheat.

Conclusion:

There is evidence that relative to wheat flour meal, for instance, cassava contributes less fat and much more fiber. Since fat is pro-obesity, which in turn is pro-diabetic/metabolic syndrome; and fiber is anti-dyslipidemic; cassava has pharmacological values to be appreciated over some carbohydrate plant-based foods.

Secoisolariciresinol Diglucoside and Cyanogenic Glycosides in Gluten-free Bread Fortified with Flaxseed Meal

Flaxseed (Linum usitatissimum L.) meal contains cyanogenic glycosides (CGs) and the lignan secoisolariciresinol diglucoside (1). Gluten-free (GF) doughs and baked goods were produced with added flaxseed meal (20%, w/w) then 1, and CGs were determined in fortified flour, dough, and bread with storage (0, 1, 2, and 4 weeks) at different temperatures (-18, 4, and 22-23 °C). 1 was present in flour, dough, and GF bread after baking. 1 was stable with extensive storage (up to 4 weeks) and was not affected by storage temperature. CGs in flaxseed meal and fortified GF samples were analyzed by ¹H NMR of the cyanohydrins. Linamarin and/or linustatin were the primary CGs in both flaxseed meal and fortified flour. CGs decreased with storage in dough fortified with flaxseed meal or GF bread after baking. GF bakery food products fortified with flaxseed meal had reduced CGs but remained a good source of dietary 1.