Nutritional Improvement of Gluten-Free Breadsticks by Olive Cake Addition and Sourdough Fermentation: How Texture, Sensory, and Aromatic Profile Were Affected?

Abstract

There is a growing need for gluten-free bakery products with an improved nutritional profile. Currently, gluten-free baked goods deliver low protein, fiber, and mineral content and elevated predicted glycaemic index (pGI). Olive cake (OC), a by-product from virgin olive oil extraction, is an excellent natural source of unsaturated fatty acids, dietary fiber and bioactive molecules, including polyphenols and tocopherols. In this framework, this study aimed at using two selected lactic acid bacteria and a yeast for increasing the antioxidant features and the phenol profile of the gluten-free breadsticks fortified with OC with the perspective of producing a functional food. Control (CTR) samples were prepared and compared with fermented ones (fCTR). Samples were added with either non-fermented OC (nfOC) or fermented for 12 and 20 h (fOC-12 and fOC-20). Our results showed that the predicted glycemic index (pGI) was influenced by both OC addition and sourdough fermentation. In fact, the lowest value of pGI was found in fOC-12, and hydrolysis index and pGI values of samples with OC (fOC-12 and nfOC) were statistically lower than fCTR. Both OC addition and fermentation improved the total phenol content and antioxidant activity of breadsticks. The most pronounced increase in hardness values was observed in the samples subjected to sourdough fermentation as evidenced both from texture profile analysis and sensory evaluation. Moreover, in most cases, the concentration of the detected volatile compounds was reduced by fermentation. Our work highlights the potential of OC to be upcycled in combination with fermentation to produce gluten-free breadsticks with improved nutritional profile, although additional trials are required to enhance textural and sensory profile.

Nutraceuticals: Focus on Anti-Inflammatory, Anti-Cancer, Antioxidant Properties in Gastrointestinal Tract

“…In assessing the well-known and marked properties of virgin olive oil components, a new scenario consists in a valorization of a by-product from extra virgin olive oil extraction, namely olive cake, a favorable source of bioactive molecules. In a previous study, we evaluated the chemical and nutritional characterization of olive cake in terms of saturated fatty acids (SFA), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), total dietary fiber, PUFAs/SFA, oleic/linoleic acid (O/L), phenolic content, and antioxidant activity [ 73 ]. Although olive cake represents a waste product of the olive oil production, it still displayed strong antioxidant activity—as measured by ABTS and DPPH assays—and high total phenol content, especially polyphenols and tocopherols.…”

“…In contrast, a diet rich in foods with a high-glycemic index is associated with the increase in circulating triglyceride levels and the reduction of HDL-cholesterol with a greater risk of suffering from type diabetes 2 due to the excessive secretion of insulin and the consequent functional loss of pancreatic cells induced by their consumption [ 79 ]. In this scenario, the in vitro starch hydrolysis of products fortified with bioactive molecules of olive cake showed a reduced predicted glycemic index (pGI) as a result of fermentation processes by lactic acid bacteria ( Figure 3 ) [ 73 ]. Other studies encompassed the mechanisms of olive cake polyphenols in protecting the hepatocytes and endothelial cells against triglyceride accumulation and oxidative stress [ 80 , 81 ].…”

“…PUFAs are those involved in the proper functioning of the organism’s biological activities, and it is currently recommended to increase PUFAs compared to SFAs [ 86 , 87 ]. Several foods are rich in PUFAs, both vegetable and animal, such as olives and olive oil, fish, soy, corn, sunflower, nuts, and sesamum and other seeds [ 73 , 88 , 89 , 90 , 91 ].…”

Anti-Proliferative and Pro-Apoptotic Effects of Digested Aglianico Grape Pomace Extract in Human Colorectal Cancer Cells

“…In the context of research interest on the nutritional value of foods and the effects of polyphenols on human health, in recent years the recovery of polyphenols also from by-products of the main agri-food industries has gained increasing importance [ 1 ]. In this scenario, grape pomace (GP)—the major by-product of winemaking processes—is intensively investigated for its beneficial and healthful properties.…”

Nutritional Quality of Gluten-Free Bakery Products Labeled Ketogenic and/or Low-Carb Sold in the Global Market

“…From a market perspective, the gluten-free diet moved from a specialty diet to a mainstream market due to consumers associating a gluten-free diet with a healthy lifestyle [ 28 , 29 ]. In fact, the gluten-free bakery market is projected to reach USD 1819.4 million by the end of 2022 and is expected to expand at a compound annual growth rate of 8.2% by 2030 [ 30 ].…”