Amylose-lipid complex (ALC) was prepared with corn starch and stearic acid and used as a shortening replacement in white pan bread preparation. ALCs were prepared using various concentrations of stearic acid to corn starch (1%, 3%, 5%, and 7%) under different temperatures (55, 65, and 75 °C) and for different durations of time (30, 60, and 120 min); then, their complexing properties were assessed using iodine reagent and X-ray diffraction. The complexing reaction at 75 °C for 60 min showed the highest complexing index of the tested conditions; the in vitro digestibility of ALC was lower than that of corn starch. White pan bread was prepared with ALCs and their characteristics, including appearance, loaf volume, and starch retrogradation during storage at room temperature for four days, were compared with those of control bread. With increasing ALC replacement concentrations, loaf volume and shape were significantly affected; however, starch retrogradation was significantly retarded and energy value decreased by ALC replacement. Overall, 50% replacement of shortening by ALC appeared to be a reasonable level for retaining the basic characteristics of the bread while retarding the staling process. These results indicate that ALCs may be potentially useful in the bakery industry for preparing low calorie and low-fat products.

In recent years, the bakery industry has been exploring alternative fats to replace traditional solid fats. Shortening, a common baking ingredient, is produced through the hydrogenation of vegetable oils, resulting in high levels of saturated and trans fatty acids, despite its vegetable oil origin. The excessive consumption of these fats has been associated with negative health effects, including dyslipidemia and cardiovascular issues. Oleogels, incorporating hydroxypropyl methylcellulose (HPMC), xanthan gum (XG), and olive oil, were utilized to replace shortening in the production of white pan bread. The substitution of shortening with oleogel in the white pan bread preparation demonstrated potential reductions in saturated fat, trans fat, and the ratio of saturated fat to unsaturated fatty acids. Specifically, with the complete substitution of shortening with oleogel, saturated fatty acids decreased by 52.46% and trans fatty acids by 75.72%, with unsaturated fatty acids increasing by 57.18%. Our findings revealed no significant difference in volume between bread made with shortening and bread with up to 50% shortening substitution. Moreover, when compared to bread made with shortening and 50% oleogel substitution, no adverse effects on the quality characteristics of volume and expansion properties were observed, and the retrogradation rate was delayed. This study suggests that incorporating oleogels, formed with hydrocolloids such as HPMC and XG, to replace shortening in bread, in conjunction with traditional solid fats, provides positive effects on the quality and nutritional aspects of the bread compared to using oleogel alone. Through this study, we demonstrate the use of oleogels as a healthier alternative to shortening, without reducing the bread’s quality, thus offering a practical solution to reduce unhealthy fats in bakery products.

Branching enzymes (BEs) are essential in the biosynthesis of starch and glycogen and play critical roles in determining the fine structure of these polymers. The substrates of these BEs are long carbohydrate chains that interact with these enzymes via multiple binding sites on the enzyme’s surface. By controlling the branched-chain length distribution, BEs can mediate the physiological properties of starch and glycogen moieties; however, the mechanism and structural determinants of this specificity remain mysterious. In this study, we identify a large dodecaose binding surface on rice BE I (BEI) that reaches from the outside of the active site to the active site of the enzyme. Mutagenesis activity assays confirm the importance of this binding site in enzyme catalysis, from which we conclude that it is likely the acceptor chain binding site. Comparison of the structures of BE from Cyanothece and BE1 from rice allowed us to model the location of the donor-binding site. We also identified two loops that likely interact with the donor chain and whose sequences diverge between plant BE1, which tends to transfer longer chains, and BEIIb, which transfers exclusively much shorter chains. When the sequences of these loops were swapped with the BEIIb sequence, rice BE1 also became a short-chain transferring enzyme, demonstrating the key role these loops play in specificity. Taken together, these results provide a more complete picture of the structure, selectivity, and activity of BEs.

For this study, microwave vacuum drying (MVD) was combined with ultrasound-assisted extraction to compare the effects of different ethanol volumes on ponkan extract and to evaluate the total phenolic content (TPC), total flavonoid content (TFC), and total ascorbic acid content (TAAC). High-performance liquid chromatography with photodiode array detection (HPLC-PDA) was used to analyze the flavanone contents and antioxidant activity of ponkan (Citrus reticulata) peels. The experimental results showed that the TPC and TFC increase with ethanol volume. Ethanol extraction (75%) showed significant advantages by increasing the TPC to 17.48 mg GAE/g (DW) and the TFC to 2.96 mg QE/g (DW) of ponkan extract and also exhibited the highest antioxidant activity. The TAAC improved along with increased water content. Water extraction showed the highest content (13.07 mg VitC/100 g, DW). The hesperidin content analyzed by HPLC-PDA was 102.95–622.57 mg/100 g (DW), which was the highest among the flavanones. Then, the ethanol insoluble residue extracts were taken from the pectin with four different solvents, evaluating TPC, TFC, and antioxidant activity. The TPC, TFC, and antioxidant capacity of pectin are significantly lower than those of the peels. Combining MVD and 75% ethanol with ultrasound-assisted extraction in the pre-treatment process can effectively eliminate polyphenols, flavonoids, and other compounds, thus enabling the extraction of high-methoxyl pectin. The total dietary fiber (TDF) content of MVD ponkan by-products was 25.83%. Ponkan by-products have the potential for the future development of functional foods and supplements.