Development and Optimization of Djulis Sourdough Bread Fermented by Lactic Acid Bacteria for Antioxidant Capacity

Abstract

This study developed a nutritionally valuable product with bioactive activity that improves the quality of bread. Djulis (Chenopodium formosanum), a native plant of Taiwan, was fermented using 23 different lactic acid bacteria strains. Lactobacillus casei BCRC10697 was identified as the ideal strain for fermentation, as it lowered the pH value of samples to 4.6 and demonstrated proteolysis ability 1.88 times higher than controls after 24 h of fermentation. Response surface methodology was adopted to optimize the djulis fermentation conditions for trolox equivalent antioxidant capacity (TEAC). The optimal conditions were a temperature of 33.5 °C, fructose content of 7.7%, and dough yield of 332.8, which yielded a TEAC at 6.82 mmol/kg. A 63% increase in TEAC and 20% increase in DPPH were observed when compared with unfermented djulis. Subsequently, the fermented djulis was used in different proportions as a substitute for wheat flour to make bread. The total phenolic and flavonoid compounds were 4.23 mg GAE/g and 3.46 mg QE/g, marking respective increases of 18% and 40% when the djulis was added. Texture analysis revealed that adding djulis increased the hardness and chewiness of sourdough breads. It also extended their shelf life by approximately 2 days. Thus, adding djulis to sourdough can enhance the functionality of breads and may provide a potential basis for developing djulis-based functional food.

Nutritionally Improved Wheat Bread Supplemented with Quinoa Flour of Large, Medium and Small Particle Sizes at Typical Doses

“…Replacing wheat flour with different quinoa particle sizes at typical doses had a significant effect on the sensory quality of bread, i.e., the taste, smell, crumb structure, appearance, and overall acceptability. Our results fall in line with other research studies that highlight that bread with 5 and 20% quinoa flour proportion had an overall acceptable sensory quality [ 48 , 49 ].…”

Lactobacillus Use for Plant Fermentation: New Ways for Plant-Based Product Valorization

“…The bread produced contained higher levels of total phenolic and flavonoid compounds and increased hardness and chewiness compared with conventional bread. The addition of djulis sourdough also extended the shelf life by approximately 2 days [71].…”

“…Consumers' demand for non-dairy prebiotic foods is constantly increasing due to drawbacks related to dairy foods such as allergy, lactose intolerance, as well as lifestyle change or religious beliefs. In this context, reference [71] presents a development of a functional drink based on soy and quinoa (Chenopodium quinoa Willd) obtained by fermentation by Lactobacillus casei LC-1. This drink presents a prebiotic effect stimulating the gut microbiota and reducing the following bacterial populations: Clostridium spp, Bacteroides spp, Enterobacteria, and Enterococcus spp [84].…”

Development of Chinese-Style Sausage Enriched with Djulis (Chenopodium formosanum Koidz) Using Taguchi Method: Applying Modern Optimization to Indigenous People’s Traditional Food

“…So far, more than 200 Djulis-based products have been introduced to the market, most of these products were added in the recent years. With the rise of consumers’ health awareness, Djulis-related products are also gradually increasing their market competitiveness [ 10 ]. Studies indicate that oral administration of Djulis extracts effectively, such as lowering blood pressure, and preventing coronary atherosclerosis [ 10 , 11 , 12 ].…”