Dudsadee Uttapap

The distribution of mulberry leaf nutrients and trace elements into silkworm larvae over its development into pupa was investigated for potential novel food applications. Four stages of chronologically collected silkworm larvae, fed with mulberry leaves, were sampled. Proximate composition, vitamin A, β-carotene, mineral, fatty, and amino acid profiles were analyzed. The highest protein content was 63.68% in the fourth instar, whereas lipid was markedly highest at 31.85% in pupa. Magnesium and potassium were found to exceed the Thai recommended daily intake standard (RDI) in almost all stages, except for the potassium in the pupa. Vitamin A in the third to fifth instar was also found to be more than Thai RDI. The distinct highest zinc and fatty acid content were detected in the pupa. Monounsaturated fatty acids were detected at the highest levels in all stages. Sulfur-containing amino acids were abundant in the fifth instar. The fourth instar, the fifth instar, and the pupa are recommended as sources of protein, amino acids, fatty acids, and lipids in developing suitable food products.

Summary: Debranched starch (DBS) is widely used for the preparation of retrograded resistant starch type 3 due to its linear molecular feature. Upon application, interactions of the DBS with food ingredients can cause rheological and textural changes in cooked foods. This study aimed to investigate the individual effects of salt, sucrose and native starch at varying concentrations on gelation and rheological behaviour of debranched cassava starch (DBCS). Adding salt (NaCl; 0.5%–2.0% w/w) delayed gel formation. Frequency sweep tests of these gels indicated an apparent elastic solid‐like behaviour with or without salt. However, the gel weakened with increasing salt concentration. This result was confirmed by reduced gel hardness and gumminess. Unlike salt, adding sugar (sucrose; 5%–15% w/w) and native cassava starch (0.5%–20.0% w/w) enhanced gel formation. Gels incorporating sucrose or native starch displayed elastic solid‐like behaviour and had higher stiffness than the control. However, the dependence of their elastic moduli on frequency differed. The G′ and G″ of DBCS gels with native starch fluctuated with frequency. Texture analysis confirmed that the gels incorporating sucrose or native starch had higher strength than the control. In conclusion, salt delays gelation and reduces gel strength while sucrose and native starch show the opposite effects. Further research on the effects of other food ingredients especially protein and lipid as well as mixed ingredients on DBS gel properties is needed to gain a better understanding of DBS gel behaviours in real food systems.

Summary: The effect of incubation after debranching on the powder structure and gelation behaviour of debranched cassava starch (DBCS) was investigated. The DBCS samples were prepared by debranching 10% (w/v) cassava starch with pullulanase at 55 °C for 24 h, then incubated at 4 °C for 0, 1, 4, 24 and 72 h and recovered by precipitation with ethanol. The unincubated DBCS appeared as small, sponge‐like aggregates with a rough surface, while the incubated DBCS powders were considerably larger, looked denser and had a smooth surface. The unincubated DBCS had an A + V‐type crystal structure, whereas incubated DBCS samples had a B‐type structure. Crystallinity of all DBCSs was 20–22%. The incubated DBCSs displayed a substantially lower gel setting time compared to the unincubated DBCS, that is, the gel setting time of 10% DBCSs cooked for 10 min reduced from 242 min to 47–52 min when kept at 25 °C. The difference of gel setting time was most likely related to the type of crystal formed as well as the difference in amorphous structure, as indicated by the content of the slowly digestible starch fraction.

The conventional method to produce process flavoring is non‐continuous, time consuming, and generates a high volume of effluent. This research aimed to evaluate the use of methionine, thiamine, and reducing sugars to develop process flavorings by direct extrusion, as a potential alternative to the conventional method. The mixed substrates consisted of methionine: d ‐xylose (MX), methionine: dextrose (MD), thiamine: d ‐xylose (TX), and thiamine: dextrose (TD) at 80:20 w/w. Three barrel temperatures of the extruder were controlled at 65, 80, and 50°C, respectively, a screw speed of 30 rpm and feed rate at 3 kg/hr. Appearance, pH, odor, and taste description of the product from each mixture were determined. Volatile compounds, possibly occurred from the Maillard reaction during the extrusion were analyzed by gas chromatography–mass spectrometry. The products exhibited different levels of meaty odor and bitter taste. Those obtained from MD showed the highest L* (lightness, 85.37) and frequency for just‐about‐right in terms of taste (33.33%) and odor (60.00%). Products from MX and MD presented the highest frequency for intense taste, and higher frequency for color compared to TX and TD. More volatile compounds were detected from the use of methionine than from thiamine. The key meaty odor compounds such as dimethyl disulfide, dimethyl trisulfide, methional, and methanethiol were found in the samples from MX and MD, while only dimethyl disulfide was detected in the mixture of TX and TD. Finally, the results demonstrated that direct extrusion reaction from methionine and d ‐xylose or dextrose is a highly efficient method to produce meaty process flavorings. Practical Application: The manuscript describes the production of process flavorings that exhibited meaty flavors by extrusion process. Physical properties, volatile profiles, and sensory evaluation of the products from methionine, thiamine, d ‐xylose, and glucose were evaluated. The extruded products from methionine and dextrose exhibited acceptable color, taste, and odor and presented many volatiles compounds contributing to meaty flavors. The results revealed the high potential to use a direct extrusion process with very low effluent, compared to the conventional method, to produce meaty flavors for industrial application.

The aim of this study was to assess the impact of pectic-oligosaccharides (POSs) obtained from oxidative degradation of pomelo peel with H₂O₂ under alkaline conditions on seed germination and growth of chili using the seed priming technique. Two types of POSs (POS-I and POS-II) with different size distributions were prepared. Chili seeds were soaked in 500 ppm of POS solutions for 16 h at two temperatures, 30 and 50 °C, with moderate shaking, and then air-dried. The primed seeds were planted on wet filter paper in a Petri dish at 30 °C for 9 d and the effects of priming on germination and growth were observed. Priming of seeds with POS at 30 °C increased the germination percentage and vigor index at 9 d after sowing by 16.7–20.5% and 16.0–25.5%, respectively, whereas root and shoot length did not differ from the hydropriming. However, there were no significant differences in all growth parameters between POS-I and POS-II treatments. Seedling length and the vigor index of seeds primed with POS at 30 °C (29.3–31.0 mm, 2693.9–2914.0) were also significantly higher than those of non-primed seeds (22.9 mm, 2062). Priming the seeds at 50 °C had an adverse effect on seed germination, i.e., the germination percentage was reduced by 24.4–31.9% compared to seeds primed at 30 °C. It also resulted in a significant reduction in chili seed growth, possibly due to the inactivation of some enzymes in chili seeds.

Effects of glycerol on the heat‐moisture treatment (HMT) of A‐type rice and cassava starches and B‐type potato and canna starches were investigated. Starch samples were soaked in water or glycerol solution, adjusted to 25% moisture, and then subjected to HMT at 100 °C for 1, 6, and 16 h. Pasting profiles of all four starches plasticised with water clearly showed the B‐type potato and canna starches were more susceptible to HMT than the A‐type rice and cassava starches. The effect of HMT on the pasting properties of glycerol‐plasticised samples was inconclusive; the B‐type canna and A‐type cassava starches were altered, but not the B‐type potato and A‐type rice starches, which remained comparable to the water‐plasticised samples. Thus, the type of plasticiser as well as the environment surrounding the crystalline region, which is specific to each starch type, also affect the alteration of starch during HMT.