Grapefruit (G) parts contain abundant phenolic acids and flavonoids (PPNs and FLVs). The wastes created from exocarps, mesocarps (G wastes, GW) and waste blanching water (WBW) lead to a considerable loss of PPNs and FLVs. Here, we assessed Buntan (CB), Buntan Hayata (CBH), and Peiyu (CP) cultivars and observed considerable amounts of PPNs and FLVs. The ethanolic extracts of GW (GWE) and WBW contained gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, ferulic acid, coumaric acid, naringin, hesperidin, diosmin, quercetin, hesperetin, nobiletin, and tangeretin (GWC). GWE has previously been reported to be a relatively active antioxidant, anti-inflammatory (based on the expression of TNF-α in Raw264.7 cells), antihypertensive, and anti-hyperglycemic compound. The IC₅₀ values for antihyperglycemic activity with WBW for α-amylase were as follows: CB (27.96 ± 0.03 mg/mL) < CP (28.13 ± 0.19 mg/mL) < CBH (41.60 ± 0.16 mg/mL), and those for α-glucosidase were CB (1.80 ± 0.03 mg/mL) < CP (2.97 ± 0.29 mg/mL) < CBH (9.10 ± 0.51 mg/mL). GWC upregulated Glut4 in HepG2 cells, as well as the insulin secretion capability, and intracellular levels in RIN-m5F cells, and it downregulated DPP4 in HepG2 cells. The IC₅₀ values for the angiotensin-converting enzyme activity were: CBP (5.10 ± 0.02 mg/mL) < CB (7.24 ± 0.65 mg/mL) < CP (8.60 ± 2.03 mg/mL). Our results indicate that PPNs and FLVs present in GW are worth reclaiming.

葡萄柚（G）部分含有丰富的酚酸和类黄酮（PPN和FLV）。外果皮，中果皮（G废物，GW）和废白水（WBW）产生的废物导致PPN和FLV的大量损失。在这里，我们评估了Buntan（CB），Buntan Hayata（CBH）和Peiyu（CP）品种，并观察到大量PPN和FLV。GW（GWE）和WBW的乙醇提取物包含没食子酸，原儿茶酸，绿原酸，咖啡酸，阿魏酸，香豆酸，柚皮苷，橙皮苷，薯os皂苷，槲皮素，橙皮素，诺比列汀和橘皮苷（GWC）。以前已报道GWE是相对活性的抗氧化剂，抗炎药（基于Raw264.7细胞中TNF-α的表达），抗高血压和抗高血糖化合物。IC ₅₀WBW对α-淀粉酶的降血糖活性值如下：CB（27.96±0.03 mg / mL）<CP（28.13±0.19 mg / mL）<CBH（41.60±0.16 mg / mL），以及α-葡萄糖苷酶的降血糖活性是CB（1.80±0.03 mg / mL）<CP（2.97±0.29 mg / mL）<CBH（9.10±0.51 mg / mL）。GWC上调HepG2细胞中的Glut4以及胰岛素分泌能力和RIN-m5F细胞中的细胞内水平，并下调HepG2细胞中的DPP4。血管紧张素转化酶活性的IC ₅₀值为：CBP（5.10±0.02 mg / mL）<CB（7.24±0.65 mg / mL）<CP（8.60±2.03 mg / mL）。我们的结果表明，GW中存在的PPN和FLV值得回收。