New Sweet Potato Line having low Gelatinization Temperature and altered Starch Structure

Abstract

A new sweet potato breeding line, Kanto 116, was developed, featuring low gelatinization temperature and an altered starch fine structure. Starch granules from Kanto 116 showed an abnormal morphology characterized by cracking into granules. Starch content, amylose content and tuberous root appearance of Kanto 116 were similar to those of the control and the parents. Pasting temperatures of Kanto 116 starch determined by the Rapid Visco Analyser were 51.4 — 52.6 °C, approximately 20 °C lower than those of the control and parents starches. Onset, peak, and conclusion temperature of gelatinization, and gelatinization enthalpy of Kanto 116 starch determined by differential scanning calorimetry were 39.0 °C, 46.9 °C, 64.8 °C, and 8.8 J/g, respectively, and much lower than those of the control and parents starches. The chain‐length distribution of the amylopectin molecules, determined by high‐performance anion‐exchange chromatography, showed that Kanto 116 starch had a higher proportion of short chains (DP 6 — 11) and a lower proportion of chains between DP 12 — 28 than control and parent starches. The debranched β‐limit dextrin of Kanto 116 starch also showed that the proportion of both short and long B1 chains was different from those of the control and parents starches.

Physicochemical Properties of Sweetpotato Starches with Different Gelatinization Temperatures

“…This result also agreed with previous reports that the short chains (, DP11) inhibited retrogradation of starch [26][27][28]. Furthermore, cracking of QS starch granules was observed around their granule center, which may be caused by changes in the crystallinity of the granules [2]. These distinctive features would be the reason for the high susceptibility of QS starch granules to the action of pancreatin.…”

“…The apparent amylose contents of the sweetpotato starches ranged from 13.6% to 16.2% and were similar to starches from 16 kinds of sweetpotato cultivars [3]. The amylose content of QS starch was slightly lower than that obtained in the previous report (QS is named as Kanto 116 in that report) [2], which may be due to differences in culture conditions and analytical standards of amylose and amylopectin. It was found that the content of attached phosphate groups decreased in the order of decreasing gelatinization temperature.…”

“…Noda et al [4] reported that the gelatinization temperature of sweetpotato starches was negatively correlated with the amount of unit chains with DP 6-10 in their amylopectins. Interestingly, it was found that both low temperature-gelatinizing starches from the new sweetpotatoes mentioned above had also a high proportion of unit chains with DP 6-11 [1,2].…”

“…Kyushu No. 127 line [1] and the Quick Sweet cultivar [2], have been found and developed by the National Agricultural Research Center for Kyushu Okinawa Region and the National Institute of Crop Science in Japan, respectively. The gelatinization temperature of the two starches was 10-207C lower than that of ordinary sweetpotato starch.…”

Tratamento térmico do amido de batata-doce (Ipomoea batatas L.) sob baixa umidade em micro-ondas

“…A aparência dos grânulos do amido de batata-doce (Figura 1) foi típica desta fonte de amido, com formatos redondos, ovalados e poligonais, os mesmos relatados por Cereda et al, 2001, Katayama et al, 2002, Hoover, 2001e Matsuguma, 2006 As superfícies dos grânulos apresentaram-se lisas e sem evidências de quebras, rachaduras após os tratamentos por TTBU. Alguns trabalhos da literatura também não observaram alterações em amidos de milho normal, ceroso e de alto teor de amilose tratados por TTBU (100 °C/16 horas) com 30% de umidade (HooVeR;MANUel, 1996).…”